Any mixer promotion and mixer offer is now prohibited here, so you probably won't get adequate answers.
Why would answers to questions like what are good mixers depend on whether people are advertising them in their signatures or not?
Because it's a project where trust is the most important, right?
Trust is the key word here. You wouldn't trust 1xbit even if 4 dozen people were advertising it on their signatures. But in general, it is the mixers that people have had a good experience with previously that you would end up using.
Just be careful when you are posting about mixers. The forum restricts mixers from here, and we can't prefer anything related to mixers.
Has any account been banned before?
I think I read somewhere that you can mention the name of the mixer, but you cannot include a link, just mention the name. Simply mentioning the name may lead you to end up using a phishing link, so with the current restrictions, the forum is not an appropriate place to talk about mixers.
As far as I know, nobody has posted any mixer links, so there haven't been any bans.