I don't think cheating is that big in OFP. The problem with having to register is that it over complicates things. That's why I dislike UBIsoft and their MP setup. Usually I have to register an account with UBI to play online. The same problem would occur if you had a website of suspected cheaters. As a server admin it's simply easier for me to kick or ban the guy from my server and leave it at that. He's somebody else's problem now. Now I know that sounds selfish but that's the way a lot of people are sadly.
The biggest problem with MP that I see is the addons. I have a lot of missions that use outdated addon versions. So I end up having to have 2 or 3 versions of the same addon. This could be fixed if a lot of addon makers make future version backwards compatible. Some of them are but not all. I'm not a mod maker or coder but I know sometimes that is impossible or simply not easy. The easiest way to fix this is for servers to make a website and list all of the addons they use on the game server and the link to get them. In the server name you could give that website so any player can get a list of what your running.