Hi guys,
Whilst I can't officially comment on the Psionicist class as that is Hunter's work and not mine (I didn't see it until the same time you guys did), I can take a few guesses.
On the bonus Feat thing, I think maybe the table should be followed, and the 16th and 20th thing ignored.
As Morte so rightly said, level based bonus feats are taken formt he class feat list unless all class feats are already taken, then they can be used for any feat.
Spheres of Influence: Good question. I would myself impose a Psionic Training Feat requirement at level 1 and allow the Psion 1 sphere of influence at creation. For non-starting characters they must have been trained, so will already have a Sphere. An important point to note is that Psions don't pay Feats for thier new spheres, nor do they need to pay Feats for the abilities within those Spheres, like non-pure psions do. They can use any ability they have the skill level and sphere for. FOr gaining more at char gen, you have your starting Feats and can learn new spheres, though there isn't much point as you get them free later on. ANother way to look at it is that Psions don't get any spheres until 5th level, and the first 4 are the training time. Not ideal, but it explains the gap in the table.
Hopefully Hunter will pop up here and clarify/overrule what I have said, as rules are his area and background is MArtin's (to the best of my knowledge).
Hope I helped,
Shane