@Cenddie Alaban there is a lot to your post so I will try to tackle it in pieces.For the most popular loan types (FHA/Conventional/VA/USDA) these loans are actually regulated by the federal government.  

Of coarse Airbnb would not have much motivation to regulate and effect a third of their business.

And now buy outs are regulated as well, which is a negative.

I feel like the government will be regulating more.

Even if it is in an area with zero setbacks (unlikely outside of an urban downtown), there are generally zoning regulations that dictate Floor Area Ratio.

They will dispatch a service to fix the problem and then one of three things happens: it was either a free courtesty service, or: they will charge your account (and deduct it for next months rent, not from the sec dep, so if they don't pay, the rent is short, which will trigger a late notice that can lead to eviction), or: they will give you a written notice and enforce the rules and regulations you have signed.

@Lesley Smith Check the rules and regulations of the park.

I started to talk to the county to inquire about the zoning regulations/process but haven't heard any concrete information yet, still in process. 

so long as they are familiar with philly (licensed in PA and knowledgeable in Philly housing market as well as being experienced in hud regulations) you should be o.k.Kudos,Mary

I would say let them apply and have them have a local professional fill out your form certifying that they require a service animal as allowed per your state regulations.