You don't get a notification for a Trade Request. You only get an email when a member send syou a message. So, if it is really something you want to hear back on, send a message to the member, and not just the trade request.
I do hope that it could be done so that if you aren't active for a year it would turn off your trade assist. that would help it out. But, you send out a lot, and hope to hear back. I just usually spend a few hours and send out a ton. Hear back form half a dozen, usually. Doesn't mean trades work out, but hearing back any way is nice.
As to lopsided trades . . . I'm not too hard on people who send what some might call lopsided. I'm sure I've sent out many. For one, PP doesn't list LR and that is tough. Not all of us know exactly what a pin is considered to be "worth", and it is hard to know on everything, especially when most of us have hundreds of "wants" listed. So, just remember that next time you get one . . . the other member may not be trying to rip you off, it may be a simple inexperience. I've certainly had both myself with trade offers. I typically find that the "bigger" traders tend to ask for more than they wish to trade. Don't know if that's the majority of what's left on PP.
All in all, though, I still find PP the best place to trade. But the biggest thing is that you do have to check in to see trade requests. You don't receive notifications. So . . . keep trying! Just when you get discouraged, it seems you'll get a reply and maybe a trade! -grin-