It is fine to do it. The transmission is shifted electronically therefore when you shift it as long as u shift is properly and not hitting the rev limiter it will last normally. my car has 106k and it is fine i have been doing it for as long as i have had my car. 6years

As for the thing about the reverse thing i know that mine at least it will not engage into reverse beacuse the computer doesnt let it shift. I flash people w/ my reverse lights when they are tailgating me just by slapping it into reverse. (i can only vouch for this if is a 99 or newer accord or civic)