Hmm... I mean, in no way do *I* think you do anything wrong here, but I honestly thing there are cases of sites being sewed for such innocent stuff.
And the "if EU wanted to pay us" doesn't work at all. It is the developers' responsibility to abide to the law, however stupid it may be. Just to clarify, in no way am I an expert on this - I do recall however reading about site being sewed for not giving "the right to be forgotten".
You see, his information is not needed in anyway to provide *him* service any longer. By that logic you could have a system where posts and games are left intact, but for example the name is erased. Just as "he can provide another email" isn't the case, because whatever email he provides, even a totally random, fake, or not his, for all you know it might be another one of his mails, thus personal data. And the fact that other users don't see it doesn't make a difference - the thing that counts is that you keep it in your dbs.