Looking at the feats... none of them are really that good.
Even Chaotic Spell Recall only allows for 1 + 1(per two Abyssal feats). Without HEAVY feat investment, that's just bad. Best case scenario, an Elf spends two feats (Aligned Casting && Chaotic Spell Recall) to get 4 extra spell slots per day.
The bonus to natural attacks and turning them poisonous is pretty neat though. I think those are the strongest ones.
well... think of it this way... On level 17, your elven generalist would normally get to cast, maybe three 9th spells /day.
Now, she immediately gets to cast NINE. Nine time stops, or shapechanges/day. Someone argued that Extra Slot is superior... but, it's one level lower, and still restricted to prep-time choices. You do not need to prepare your best spells multiple times, and you get to cast your top levels like a super-sorcerer who can change their spells known daily.
You also do this a level earlier.
http://brilliantgameologists.com/boards/index.php?topic=7150.0It's not all that uber, though --- I advertised this as something a sane DM would allow. IIRC correctly, I initially thought CSR worked on all spells, and when the error was noticed, we started working on a way to make it work on every spell, back in '06. Getting that chaos descriptor with a feat would be really good, and definitely blows the 10th level substitution out of the water.
Just think of it this way - get 4 heritor feats and you make all sorcerers cry, forever. (as many spells on a new level as a sorcerer, one level early.) Well, except for the fiend-blood war weavers who turn their entire party immune to necromancy and death from hit point damage all day long... (could be bards, too.)