Well written FUD, none of those are actual vulnerabilities. They probably stopped responding to you because this is complete nonsense.
Could you please tell me where is the nonsense ? Where is the FUD ? Please quote me where I'm wrong and arguments.
They paid you a bounty for the one bug you found, which wasn't much of a security risk really. The others are not bugs and they are not paying you a bounty for them. That said, what is your goal from making this information public? It's clearly an an attempt to FUD, probably in hopes that Polo will pay you for your "bugs" in the future for fear you will spread more FUD about them.
You should really consult security pentester. They will all agree with my arguments.
As a matter of fact, I described a possible attack in my article, which, when I got the trollbox moderator privilege escalation (which wasn't mush of a security risk ? lol ?), I was able to
spread clickable buying, selling, withdraw and lending links. Sorry, but I think it is a serious vulnerability don't you ?
Don't you think I deserved, not a bounty, but maybe something like a ... reply ? "Thanks, we've corrected this bug, rest assure you can trade on Poloniex safety" ? It is the strict minimum.
I do not expect any bounty from poloniex, your theory of the conspiracy sounds a little too much.