Echo is indeed starting to remember things. But she's recalling very little, very gradually. And it's not her old life she's remembering, but instead she seems to be retaining tiny little pieces of her fake reprogrammed personalities.
Nope. Apparently the Dollhouse makes all its agents exercise a lot and stay in great shape, but that's all, nothing superhuman. (Except maybe Alpha, who is vaguely hinted to have extraordinary abilities, but we haven't really gotten that far yet.)
Aside from Handlers = Watchers, none of this has even been implied. Could happen, but basically that's just fantasy booking, and anyway the show doesn't look like it's gonna stick around long enough to get to further storylines like that.
Ah well, it seems I was wide of the mark a bit on some of my guesses. Though I still reckon if this show goes another season they'd start to go that way. Might watch this once the season is over so I can speed through the episodes and get the general story arch if its as bad as you think - just like Tru Calling.