I have lived in three marinas, none of them were resedential, and all had liveaboards in them.
The marinas were happy with this arrangement and the last thing they would want to do is discuss it with you. If they discuss it then they would have to tell you that it's not allowed, in fact there's usually a clause in the berthing agreement that it's not permitted.
In reality, as long as you keep your head down, how can anyone tell that you are living aboard unless they watch your boat for 24 hours every day? If you have a postal address elsewhere but you spend a lot of time on your boat you can be regarded as a frequent visitor, which would be your answer if you were ever challenged, which is unlikely.