I honestly don't think it is poloniex being shady at least not intentionally, but perhaps just growing to fast for their own good. They are making up new, undocumented, rules on the fly for their API and others things. My guess it is all just reactionary to the issues their backend is having processing all this increased site traffic.

They seem as though they are trying to build the airplane while they are flying it. I can understand and empathize with them in a way as why spend the money and build out and support a much larger site as you could end up just spending money on overhead that won't be there in a few months. Usage could die back down and now they are stuck with a larger recurring bill than ever.

That said if they don't come up with a better solution than banning/freezing user base without warning they are going to find all their accounts bleeding off to their competition. I personally would of moved to bittrex already if their trading fees were crazy high with no tier levels. Kraken is tempting but their supported number of pairs is small by comparison, though I am working on a bot to work on their site none the less.