I think you'll find out if you are allowed to play or not. My guess is anyone that can connect to CF can play CF, and won't get banned unless they do something wrong (or are banned and trying to circumvent that rule to still play and get caught somehow).

Whether or not you should play CF again, well that is up to you. I have to think CF is not quite the same game you remember it as if you have not played in 7 years, and you have to be ready to accept that if you want to play again, otherwise you're probably not going to have a good time.