I've seen a couple users say not to ask for up-votes. Personally, I've done it a couple times and users asked why I was doing it. However, there are questions that say to up-vote answers you like best. I've also seen users saying to "Click the green tick", which grants that user 20 points. Is it against the rules or not?
Don't ask for people to upvote you.
The BA thing is as Ty said. Some users will comment that the answer is satisfactory but don't know the BA feature, so in that instance it's ok to tell them that it exists. The alternative is that we have to go through pages of content selecting BAs ourselves