I've been selling here for 11 years. I was a powerseller for 5 years, and I've done pretty well over the years. I've been through up and down times.
In regards to your direct question, in my opinion there is nowhere to move to. Yet. That isn't to say there won't be in one, two, five years, but for me, there's no place to go now.
I looked at all the sites you and others have mentioned and I find they would be no benefit to me. Not now anyway. If that changes, I'll give them another review, but I don't see that happening in the near term.
I've just spent the past month being "MAD" and it did nothing for me. I made no money because I didn't list anything. I was more pissed at the fare hikes than I am about the feedback and the DSR system. I don't feel the feedback is going to cause me any problems. My DSR values are running fairly high and have me in the "middle 50%" of all sellers, for just doing what I always do, so I see no need to worry.
What worries me though is sales are off and I think they are off due to bad economic conditions. There is less "free" money out there to spend on "junk". Yes, I sell junk. With oil now at $110 and still rising, the dollar sinking, postage rates going up in May, Gasoline rising, less people have money to spend on junk.
Taken in perspective, I compared some sales from 2000 against sales today. Sales of the same (or close) final value were higher today, but not that much higher that I can claim I'm going broke. So, for now I'm going to keep doing what I've been doing and continue to sell on eBay.