Why Does it matter how many hours are spent on the server? You better not mention it, because this player was there, until neither you or I knew this server existed. So don't talk about things w you don't know. You pointed out what bothers you, and that's ok. You gave your opinion. He is also aware of his mistakes and vocabulary which is not ok.
Anyway, he is a longtime player, he has experience as an admin, and I would give him a chance. It is easy to solve it later if there is no progress.