Duskblade and apprentice feat?

[Italscratch]

Greetings,

as title suggested, I have few questions about these two. Soon my group will be playing campaign in Faerun setting and I'll be playing Human from Halruaa. Thing is, he'll start as human paragon (and take speak language as his class skill) and proceed to raise levels in duskblade later.

1. Is he eligible to take apprentice feat in his Spellcasting variant? (as he has no spellcasting ability on 1st level hum.paragon)
2. Does Spellcasting feature enables him to add new spell every time he raises to a level where he gains new spell level slot or he only adds spell on 1st level and can switch that one later?
3. I see you get +1 modifier if your mentor is of same class as your own. I presume I could take wizard or sorcerer or whomever as a mentor as long as he is arcane spellcaster? Question is, can I as a Duskblade, add spell from wizards spell list or I only add spells from Duskblade list? Probably the latter.
4. Spellcasting gives UMD as a class skill for max ranks in it (nice for Duskblade) but it also states that class gained  later must have it as a class skill or what? I must add 2 ranks to raise it by 1 but still can have it maxed?

Thanks in advance for any answers, I didn't want to go deep into the character, just want these technicalities explained a bit.

[NunoM]

1. I don't think a human paragon is elligible for the apprentice - spellcasting feat. You don't exactly have a class that can be associated with your mentor. I suggest you start off as a Duskblade and only then take the human paragon...

2. The Spellcasting feature grants an additional spell at 1st level. For a spontaneous caster (like the Duskblade), it also allows exchange a spell the caster already knows, for another one of the same level, every time the caster gains a level in that spellcasting class.
 Example: As per the Duskblade class description, he can only exchange a spell known at 5th level and every subsequent odd-numbered level. Even then, the character can only trade a spell two levels lower than the highest level he can cast (which means you can only trade a 1st level spell at 9th level!).
 The spellcasting feature allows you to trade a spell every level.

3. The mentor can be of any arcane spellcasting class, but if it is of the same class as the character, that modifier applies to the level of the mentor. You should definitely consider having a Duskblade mentor. Huge benefits in that.
  The Duskblade's spell class list doesn't change, so you're still limited to learning spells from that list. If the mentor is a Duskblade, this is a no-brainer.

4. The description of the feat is clear: "These new class skills are added to the class skill list for any character class or prestige class she gains". This means that the skills will always be class skills (i.e. 1 skill point = 1 rank), no matter the class.