Druid//egoist seems a bit excessive on the magical aspects that dont really have much of a changable fluff to biology, too many spells/powers without a 'natural' explanation.
Depends entirely on how you fluff it. Any psychometabolism power involves altering your own biology and others', and a lot of metacreativity powers can be (very slightly) refluffed into you laying an egg which matures into a creature (Astral Construct), or expectorating a substance (Psionic Grease, Entangling Ectoplasm, or even Wall of Ectoplasm, for a solid wall of webbing). And then you have wild shape and Metamorphosis, which are obvious.
It'd be easy enough for me to refluff things, and given the width and breadth of Ex abilities in the game, even energy powers could be firing spitwads that burst into flames or contain a chemical mixture that contains liquid nitrogen.
Druid/totemist, and egoist//totemist sound up my alley, what are the pros and cons of each?
Both are really powerful, though druid has more early-game power and egoist has more late-game power (and egoist tends to be a lot more feat-intensive). And whenever you wild shape or Metamorphosis, you have to be careful that your forms have space for the soulmelds you have shaped and bound.
Psicrystals are more awesome than animal companions overall (IMO, anyway), but you can't share your soulmelds with them (while you can with animal companions via a feat).
Tashalatora (I commend you if you spelled that correctly from memory)
I did.
seems like another possible alternative, so, how would that build fare against the other two? Barring crazy shenanigans of course
It's quite good. Psywars are Wis-based, and with Tashalatora you get a bunch of monk goodies, and both stack up VERY well with druids and wild shape. Most psywar buffs work exceedingly well with animal forms, and all those extra unarmed strikes on, say, a bear, is just gravy.