I'll have this first post be Spoiler-divided to keep things smaller and more easily understood:
I'm looking at SRD spells that are related to Remnants, just so you know. Also doing it alphabetically as I go through Remnants.
1. Acid: All SRD Acid descriptor spells are Conjuration(Creation), not Evocation. This is because Acid is typically done as physical material. Fluff-wise, Acid Evocation would be spontaneous corrosion by direct energy application. This overlaps with Transmutation, though.
2. Bludgeon. Either this is supposed to have the Force descriptor or it's supposed to be Transmutation, like Telekinesis.
3. Build. I assume this is supposed to be a Fabricate Remnant, but that spell is a Transmutation spell, not Conjuration. Conjuration(Creation) is creating material/creatures from just magic.
4. Disarm. Telekinesis is a Transmutation spell, not Evocation, though the change is sensible.
5. Grapple. Again, Telekinesis is Transmutation.
6. Peirce. Either Transmutation, if Telekinesis is followed, or it's missing the Force descriptor.
7. Pressure. If you are having force application without cause be Evocation, it should be Evocation [Force]. Consistency is key, here.
8. Push. Again, Telekinesis is Transmutation. Pressure is Transmutation, so either this, and Peirce, Disarm, Bludgeon and Grapple are supposed to be Transmutation, or they need to all be Evocation [Force].
9. Slash. Missing Force descriptor, or should be Transmutation.
10. Trip. Either needs to be Transmutation or you have inconsistency with the Transmutation/Evocation [Force] thing in regards to Telekinesis effects
First, the listing. The thing where you repeat the listing of Remnants by class for their point cost could be rolled into the statblock. There's nothing stopping you from taking the PP cost line of Psionics and giving it for each class under abbreviation as part of the alphabetical listing. It'd make the Remnants more self-contained, making the process of additional ones from sub-forum readers, and you, easier.
Second, the fact that you can cast unlimited Remnants per round, limited only by RP/round is kinda busted in some cases. For example, a Remnant Mage of 7th level that selected Build for Practiced Remnant is crazy for crafting. The single most expensive thing on the SRD, Full Plate, costs 1,500 GP with a craft DC of 18. At 6th level, when you can first meet the DC 18 check, provided you selected Build for Practiced Remnant, make it in 47 rounds. Making a Masterwork suit at 7th level, needed for Masterwork's Craft DC 20 to be met, is 44 rounds of Build time. Or they can be tossing out a swarm with +7 to attack rolls dealing 21d4 damage per hit, lasting three rounds and moving 50 ft. per round, every round, instead of making Masterwork Plate Mail in 44 rounds. Or 21d2 with 18-20 crit range, if they swap Greatswords for Falchions.
Third, the lack of flexibility. Oh, sure, there's plenty of Remnants, but combinations of them are rather limited. You really only have Spellforms for outright mergers of them, with combining them without that being harshly limited by the lack of available overlapping effects. Weapon's minuscule cost makes it virtually always better to make more Weapons than to enhance one of them by any of the methods available. The Enhance Remnant can give, at best, +2d6 damage and +3 attack for 10 RP. 10 RP instead gives +1d4x10 damage from just making more Weapons. You can also... Do Undeath+Enervate and some buffs, I guess.
Fourth, and starting on the positive, the infinite use mechanism works out really well, outside of abusable things like Weapon giving 1d4 damage per round per cast for it's duration. Most of the abusable stuff comes from the core rules being broken, rather than the system. Build is only broken because mundane crafting is. It's considerably less broken than Fabricate, except for the fact that it's at-will usable and breeches the skill rank cap easily on Remnant Mage. The way ratios are build into other parts of it keep everything coherent and create an actually seemingly unique system of save gradient that serves to replace more typical DC increase methods. Ten uses of Acid is DC 20+score for negation, but getting off a save of 10+score halves, with each point past that cutting off another 1d3 damage. This prevents the weird all-or-nothing of the typical system, though it keeps the weird jump in effectiveness, that's needed to be sure you're getting somewhere with damage.
Fifth, and really just extending the previous statement, the DC system works out wonderfully. All the all-or-nothing effects increase their DC by 1 per 2 castings, which means that a 10th level Remnant Mage can get DC 15 Deafen, or DC 17 if they grabbed Practiced Remnant for it. Similar performance to Heighten Spell for 3 RP effects on that. The DC scaling, and often effect scaling, being stronger is offset by less area-effectiveness and being practically knife fight range compared to actual spells.
Sixth, the free-action casting allows crazy build choices. Shift lets you teleport 5 ft. per 4 RM, which means that you can, as mentioned earlier, use it to get Charges far easier. However, there's another factor to think of with it. Being Free Action means it can be done in between every action you make. So Shift is functionally a second set of five-foot-steps. This also means that Ascend combined with Shift gives virtual flight by teleportation while floating.
The spellforms are really inflexible. And awkward. And horribly named, in terms of access feats, which need to be giving more coherently-themed effects to allow thematic naming. One of the things that stuck out to me when reading through the thread was an earlier concept of Spellforms named Spell Constructions. The discussion surrounding that makes me think of a more literally Vancian system, with spells being actually cast as lengthy ritual affairs and then stored to have the last touch applied. As-is, the Vancian Casting of D&D only has fluff to back this.
So, cast each given Remnant requirement in turn, spending a round on each Remnant, then get effect at the end. Or delay getting the effect, which is the first divergence from the proposed setup for Spell Construcitons. Instead of recasting all of the component Remnants to refresh a Decay setup, that part could be rolled in automatically as an upkeep cost, with fluff making it reasonable for Magicians to not actually lose their daily amount. So each one you have prepared cuts into the amount you get per turn until you actually use it, making it so that having a bunch readied reduces Remnant output.
Then, for improvement at later levels, instead of level scaling, it'd be using Remnants as boosters. Stacking up what that Remnant does in the combination, again eating time for casting it now, and per-turn output along the way, to loose a big trick later. It generally means that there'll be a nova every time there's enough time to set one up, so casting time is a thing that's needed. Swift-action cast keeps it to one casting per round without extra actions, while retaining the typical gish-friendliness of the system. Additionally, some sort of reserve effect for having it ready, possibly a partial casting that doesn't require reconstructing it, could improve incentive to hold onto the spells instead of just tossing them off and spamming Remnants at full capacity again.
Thoughts on anything in this post?