This has pretty massive potential provided you find the right balance among the Guild's various personalities and identity related abilities. There are a fair number familiar with the system as is and the nebulous, largely undefined existence of the Guild as a meta roleplaying concept gives access to just about any environment. At the same time I admit I have no idea how you intend to "balance" anything beyond a Gentleman's Agreement of the players to not come unhinged with their builds, or if you have some limit in mind in particular.
@catchamber, I would offer the strong suggestion, in addition to those hard limits, having a closer interpretation of "Read As Intended" (RAI) versus some of the "Read As Written" (RAW) usual tricks and the general Gentleman's Agreement I referred to. That way we are not seeing anything from Diplomancers, Planar Shepherds, Red Wizards, Dweomerkeepers and the like. The builds are almost universally transparent and recognized now too, so it would be easy to say, "That's not really appropriate, do you think you are X, Y and Z, really?"
That's not to say a character should not be allowed to invest heavily in Diplomacy, or a warlock prevented from going binder so they can then prestige into Hellfire Warlock to do powerful Eldritch Blast casting, or a sorcerer from being a Swiftblade/Abjurant Champion/Spellsword/Dragonslayer and so forth. Just that the over intent is to provide a standard of "Reasonable optimization for the purposes of roleplaying an archetype rather than optimization for the purpose of raw power."
That and I would play cards like what you described with magitech and psitech close to your chest as the Dungeon Master. Artificers, especially Psi-Artificers do not need any added help or incentive.
@catchamber Throwing in interest. If we're playing in 3.5, basically every one of the dozens of rulebooks can be downloaded for free. Don't know what's in the SRD, but I'd guess it's a mix of the core rulebooks and Unearthed Arcana. I'm a little of a supplement librarian personally.
I plan to play an air elemental monk, if you're okay with monster PCs.