Federal Laws Prohibit Discrimination of 7 Protected Classes, Massachusetts has added 8 more:-02.Always know more of the Rules/Laws/Regulations than ANY Tenant.

I’m wondering how I can protect myself if they somehow rack up the bills/ abuse the policy. 

So your saying select No Damage Protection and just submit an extra charge when it's warranted? 

The bottom line is this: Concealment is not asset protection, proper (time consuming and expensive, I know) management, and good, prudent, practices (ditto), WHICH ARE ADHERED TO, and insurance (expensive), are needed for asset protection.

If you did and had problems leave them a review with the Better Business Bureau, here and also contact the FTC Consumer Protection division.

But consumers sued them all too many times and for too much money.

Holding properties in an LLC (or other legal entity) can offer valuable protection for your personal assets, so I understand why you went that route.

Asset Protection Trusts don't protect assets?  

Unfortunately, that is an expensive time-consuming process.

However, expect greater transparency and heightened consumer awareness that has come out of media attention and NAR settlement to impact the listing component of seller agency as well.