He approached the squatters still said it's their house than bought 2 big dogs to keep him off their property.

I am  assuming dogs or cats here. 

He came in and said "You have 15 minutes to pack an overnight bag & get yourself, your girlfriend & dog out of the premises & off of the property.

You can bird dog for them and maybe drive/bike around to look for homes that look distressed.

That term is misused by many as a dog whistle for "working-class black neighborhood" throughout the US, but that's not why the term was created. 

I'd sit down and ask them what protects you from their mis-behavior or mistakes as your agent?

If the HOA can assess fines you want a clause that HOA  fines and fines issued by the town that are a result of tenant behavior the tenant will responsible for (e.g. noise violation, lawn too long, sidewalk not cleared).

If talking to family (assuming this is extended family/friends and not your nuclear family) is what is shaking your confidence, then I would not continue to engage in that behavior.

They also have dog kennels and a horse stable. 

Technically speaking it may be possible to find an opportunity that will let your friend do the same, presumably in exchange for something like lower fees.Practically speaking it may be a lost cause and could result in more trouble than its worth.Don’t let the tail wag the dog...