Personally I don't see any problem with the username. It's pretty clear that his name is in there, and a related company name. The name itself does not "promote" the company. If his username was "You should hire Acme Co" that'd be different.
His BIO is definitely within what's allowed. It's his place to brag about his accomplishments and undertakings. If those read out as a CV/Resume/Blatant pleading for employment, then so be it. There's no mandate in the general use of the site to ever see that.
I have not seen the content of his answers, but they would be of the most concern to me. If he is constantly promoting himself or his business then that situation is clearly addressed in the [FAQ]. If his answers have no mention of his business or available services then he's contributing to the community and that can't be wrong.
Just looked over several of their posts, no mention at all of the company or availability of employment. Looks like their on the up and up to me.