Linked Power metapsi, is another work around. And crafting powerstones.
The Psicrystal is a Bonus Feat, and can also be a target of the ACFs. So you can ditch both the psicrystal and the other bonus feat, for 2 of the acfs. I don't think the language for Discipline is loose enough to allow 2 Disciplines.
Uniques has been argued plenty (maybe '12 the last solid debate) about the Per Level Per Day trickiness/nonsense/goodstuff. 3.0e Erudite used effectively that too, just like the vance casters. Obviously it's more powerful that way, by my estimation catching up to Wizards around level 13 with 7 7s per day (assume Wiz has bonus slots).
Multiclassing and PrC-ing is hard limited, though some have argued PrCs were not supposed to be in there.
I don't know if Nijineko's errata file from BRC, addresses anything specific about Erudite. Perhaps Niji can send you a copy. I never bothered (grumpy says they coulda done it the right way grumpy wtf)
"Original" is worth the feat early, but it's Learn list is duplicated by the Expanded Knowledge feat. Level 7 is a good spot to get out of Original.
"Mantled" would allow 20 off list powers per level, on time.
"Discipline" would allow 1 discipline of powers per level, on time ... and transparency School Spells via a Chameleon Crafting feat
(or two) from Dr#349. Needs a prereq feat which can be tricky. Clearly weaker than the other options until the feats come on line, and there's enough Magic Mart access.
"Spell To Power" hei wats dat? Ultra early qualifying spell point wizard, though still needs a Magic Mart.
Magic Mantle with a very T.O.-ish slant, gets Magic PrCs into play. Probably not OK at most tables.
Retraining from one ACF into another and back, to pump up the repertoire even more. Also probably not OK, even though technically legit.
Substitute Powers on the mantles "ought" to be OK, but the argument/reasoning chain might be lost by now.
Basic stupid proof build Orginal Erudite 7
1) ... Elemental Envoy, gets most mileage out of this
b) ... Powerstone
h or flaw) ... +1 Unique (wtf it's called)
flaw) ... open for prc qualifiers if necessary
3) ... Linked
5) ... Psi Meditation
6 and 7 get retraining either feats or 1 ACF, or prc prereqs.
7 is the PsyRef loop point, where you fill up powers yourself and give a very small
to Wizards that can't do this. Erudite suffers the same problem as Archivists and Wizards up to level 7, in that a DM can gimp them willy nilly.
Magic Mantled Erudite 7 / Nar Demonbinder 1 / Cerebremancer 6 / Erudite +X and the specific Psiotheurgist feat from Dr#349 ... is the
one standout multiclass/prc combo that an Erudite can do better than any other.
edit --- StP Erudite 7 / UrPriest 2 / Psychic Theurge
6 / then debate whether to go E 8 or PT 7 first, then the other / Erudite +X ... is a decently normal Triple 9s build.
Epic? No not really.
But the StP has a strong incentive to not go Epic Powers(Spells) and instead get 10th Level Power access, to open arcane 9s to the StP goodies.
Disciplines are obvious.
Mantles aren't but a Substitute Powers Mantle could easily be entirely one subschool of a discipline.
Original can learn all psi 9s, if it goes to 10th level Powers. Not nearly as strong as StP, but makes Epic Psi seeds easy.
R.A.I. Erudite can be throttled back more than a Psion.
scratch that itch CapQmore edits --- the 2 feats at the bottom of the mind's eye erudite stuff, the level 3 feat allows early qualifying trickery that the Erudite can't really use, but the repertoire feat is a good one, worth taking multiple times perhaps with the right build, which of course the glory days would have found ... oh they'll pass you by glory days in a wink of a Psion's eye glory days.
Discipline Evocation/Psychokinesis can get spell point Divine Power on time, and similarly Miracles. That's the Erudite Gish right there (such as it is).