Regulation just means some people will flock to unregulated networks (like my own ..) .. So it is hardly the 'end of bitcoin'
I don't really understand the function of bitcoin mixers (yes even if I have a sig campaing of a bitcoin mixer running). My question is: how do you know the bitcoins you get are clean and not stolen or criminal related? can't this be a problem for you?
You won't know. You might get the cleanest coins in history or something freshly stolen. The point is that no one else will be able to tell either.
Unless they have solid evidence connecting you to any crime directly, they won't bother with you. Also, they would be going through a known mixer address so people would know it would be fruitless to trace any further.