I don't think you should have any problem having your boyfriend living with you. I am assuming you live in a condo. I am not familiar with senior rental communities and perhaps they have different rules.
I sell many condo's and single family homes in "adult" communities and the major rule is that at least one owner must be 55 or older. Most, if not all. of these type communities have in their by-laws that no one under the age of 18 or 21 may reside full time with the owner.
In any event you should check with your property manager to make sure exactly what are the rules and regulations.
No. if it is an 'over 55' community, that means that you have to be over 55 to live there on a permanent basis. Having said this - there are exceptions in many area's with visitors (grandkids, etc).
I would talk to the property mgr and see if you can work something out legally with your situation.