I'm at the spot right before the 'Point of No Return', is this my last chance to get figments and stuff from others' brains, ever? (as in I'll never get to back until I finish the game)

There is one of those teleporting whatsits after the point of no return which you can use to return to the collective unconscious, but you will be unable to return to either the camp or the asylum after the point of no return as the portal to Sasha's lab will no longer be there. :)

If you still have stuff to do, I wouldn't recommend going past the point of no return as there is no opportunity to return to the camp or asylum at all afterwards.

Awesome. One more question, is this pretty much it? End of game? *sniff* It's like finishing a good book - don't want it to end.

Once you plough through the last level which the point of no return leads onto, yes. :~