Another Eldritch Glaive rules issue... Let's get this over with.
Starting with the base, Eldritch Blast is specifically called out as a ray on page 7 of Complete Arcane. "Eldritch Blast (Sp): (...) An eldritch blast is a ray with a range of 60 feet. It is a ranged touch attack that affects a single target, allowing no saving throw." Pretty clear and defined overall.
Then Complete Arcane 71-73 talks about weaponlike spells and abilities and which feat work for what. Eldritch Blast is specifically called out as weaponlike on page 71. Page 72 starts the section of "Feats and Weaponlike Spells" and defines two categories of weaponlike spells: Ranged spells and Touch spells.
"Ranged Spells: Ranged spells include those that require ranged touch attack rolls, such as rays or hurled missile effects (examples include Melf’s acid arrow and lesser orb of acid, described on page 115). This category also includes spells that generate effects that act as ranged weapons and require ranged attack rolls (but not ranged touch attack rolls), such as decapitating scarf or fire shuriken (described on pages 102 and 107 respectively).
Touch Spells: Touch spells include any damage-dealing spells with a range of touch."
To make the typing easier I'm just going to make them initialisms: Ranged Spells is hereafter RS and Touch Spells are hereafter TS.
It then defines which feats are eligible for both types of weaponlike spells. Summarizing it:
Improved Critical can be chosen for either RS or TS and the weaponlike spell will have its base crit range doubled (usually from 20 to 19-20).
Improved Unarmed Strike allows dealing Unarmed Strike damage along with delivering a TS if you use a regular melee attack instead of a touch attack to deliver it. If you miss the spell is not discharged.
Point Blank Shot grants a +1 to both attack rolls and damage rolls for RS within 30 feet. Spells that don't deal hit point damage don't get the +1 to damage, but they keep the +1 on attack rolls.
Precise Shot means you can fire a RS at a creature engaged in melee with something and you won't get the -4 for it.
Stunning Fist can be used with unarmed strikes used to deliver a TS.
Weapon Finesse allows the character to treat TS as light weapons and thus use Dex for attack rolls instead of str.
Weapon Focus can be chosen for either RS or TS and the character will get the +1 to attack rolls with it.
Note that Power Attack is missing from the eligible feats.
And then Eldritch Glaive comes in and muddles things up. The text reads as follows:
ELDRITCH GLAIVE
Least; 2nd; Blast Shape
Your eldritch blast takes on physical substance, appearing similar to a glaive. As a full-round action, you can make a single melee touch attack as it wielding a reach weapon. If you hit, your target is affected as if struck by your eldritch blast (including any eldritch essence applied to the blast). Unlike hideous blow (Complete Arcane 134), you cannot combine your eldritch glaive with damage from a held weapon.
Furthermore, until the start of your next turn, you also threaten nearby squares as if wielding a reach weapon, and you can make attacks of opportunity with your eldritch glaive. These are melee touch attacks.
If your base attack bonus is +6 or higher, you can (as part of the full-round action) make as many attacks with your eldritch glaive as your base attack bonus allows. For example, a 12th-level warlock could attack twice, once with a base attack bonus of +6, and again with a base attack bonus of +1.
The first things to look at are: Is it technically a weaponlike spell effect? It is definitely not a Ranged Spell, but it's also not a Touch Spell. Touch Spells are defined at
http://www.wizards.com/default.asp?x=dnd/glossary&term=Glossary_dnd_touchspell&alpha=T as "A spell that delivers its effect when the caster touches a target creature or object. Touch spells are delivered to unwilling targets by touch attacks."
PHB 175 also defines Touch Spells.
"Touch: You must touch a creature or object to affect it. A touch spell that deals damage can score a critical hit just as a weapon can. A touch spell threatens a critical hit on a natural roll of 20 and deals double damage on a successful critical hit." And that's also why Improved Critical can work on it.
The SRD also lists it here.
Touch Attack is then defined by the glossary as "An attack in which the attacker must connect with an opponent but does not need to penetrate armor. Touch attacks may be either melee or ranged. The target's armor bonus, shield bonus, and natural armor bonus (including any enhancement bonuses to those values) do not apply to AC against a touch attack."
PHB 136 also defines Touch Attacks:
"Touch Attacks: Some attacks disregard armor, including shields and natural armor. For example, a wizard’s touch with a shocking grasp spell hurts you regardless of what armor you’re wearing or how thick your skin happens to be. In these cases, the attacker makes a touch attack roll (either ranged or melee). When you are the target of a touch attack, your AC doesn’t include any armor bonus, shield bonus, or natural armor bonus. All other modifiers, such as your size modifier, Dexterity modifier, and deflection bonus (if any) apply normally.
For example, if a sorcerer tries to touch Tordek with a shocking grasp spell, Tordek gets his +1 Dexterity bonus, but not his +4 armor bonus for his scale mail or his +2 shield bonus for his large wooden shield. His AC is only 11 against a touch attack."
Taking into account what a Touch Spell is versus a Touch Attack, we clearly see that Eldritch Glaive is
not a Touch Spell. It is a spell(like) ability, but it is not a Touch Spell. Thus, strictly-speaking, it does not qualify for Weapon Finesse because it's not a Touch Spell.
So now we have to ask: What
is Eldritch Glaive? Obviously it's effectively a spell effect, but neither Complete Arcane nor the PHB seem to define true melee weaponlike spells or indeed spells that effectively create a melee weapon.
So let's look at a spell that does create a melee weapon:
Ice Axe.
As can be read in its description, it creates a battleaxe-shaped shard of ice. Attacks with it are melee touch attacks, the character does not get strength to damage because it's virtually weightless, and the character can make iterative attacks with it on a full attack like a normal weapon.
Comparatively-speaking, Eldritch Glaive gives a shitty description, but both have their issues. Does Weapon Finesse work with either one? Not listed, although because Ice Axe says it's virtually weightless one could reasonably conclude it could benefit from Weapon Finesse. There's really nothing to work with in Eldritch Glaive's description other than saying it gives Eldritch Blast "physical substance."
Does the "weapon" get str to damage? Ice Axe says no, Glaive says nothing either way other than saying the weapon has "physical substance" which could go either way since an Ice Axe definitely has substance (barely) but it doesn't get str to damage.
How can the weapon be wielded? Ice Axe heavily implies it's pretty much a 1-handed weapon since it says it makes something "battleaxe-shaped" and it says it doesn't allow for str to damage, so it's not going to benefit from being held in two hands. Eldritch Glaive likewise doesn't give specifics and merely says the weapon formed is "similar to a glaive." From that we could imply that it's meant to be used in two hands since that's how actual glaives are used, but the sentence "Unlike hideous blow (Complete Arcane 134), you cannot combine your eldritch glaive with damage from a held weapon." implies one can wield the glaive while still holding an actual weapon. It also doesn't have the Ice Axe language of "If you choose to hold something other than the ice axe in your hand or use the hand in some other way, the ice axe vanishes until the hand is empty again."
Can Power Attack be used with either one? Neither one is explicit about this, but Ice Axe implies it probably wouldn't since not getting str to damage means no matter how hard you swing it, it won't do extra damage.
At least both are comparable because they're specifically melee touch attacks. But neither one can technically benefit from Weapon Finesse.
Quick damage comparison I suppose: Ice Axe is Cleric 3, thus its bonus to damage is +2 minimum usually. It's a standard action to cast but sticks around for CL rounds and doesn't require using an action to keep around past the initial casting. The tradeoff is it can only be cast once, maybe twice a day at 5th level.
A roughly equivalent amount to 2d12+2 is 4d6, which can be had at warlock 7. EG takes up an entire full action (not a full attack, it's a full action) to use. The warlock can do that all day though, while a 7th level cleric can only use Ice Axe 3 times a day just through base 3rd and 4th level spell slots.
Just comparing EG straight to Ice Axe, it's reasonable to say it wasn't intended to get str to damage. The only reach weapons I know of that allow for Weapon Finesse are exotic ones so one could argue that besides EG not being a Touch Spell effect preventing it working with WF, a reach weapon of any size (light, 1h, or 2h) isn't meant to benefit from WF isn't meant to benefit from WF unless you spend another feat to allow that.
