As a local investor and agent here in Columbus, let me know if you have any questions or want to connect!

Rents (dependent on the local area and subdivision, but for sake of this sample, let's use this #) = $1,700 to $2,000.3/2 mobile home vintage 1980s with 1200 sq ft in our area:  Cost $10,000 - 25,000.  

I think its highly regionalI would talk to a very experienced local RE broker they will know. or a local Appraiser. 

If so perhaps the state requires you to have a local “registered agent” for purposes of receiving legal notices.

I would go to local real estate meetups and find a mentor.

A property in Allentown, may seem convenient in location, be really close to promising comps, and have good valuations, but only a local expert or someone from the Pittsburgh Area would know that you probably have the market area too wide. 

How would an appraiser determine value without local, recent comps?

But in some jurisdictions there are no local laws prohibiting it and likely few to no local law enforcement will enforce federal laws...But, I think the point you are trying to make is worth noting - it is no longer hidden or considered taboo. 

Also 4th quarter of last year Packwood and county officially did discuss potentially regulating STR's by either limiting numbers or adding a tax to cover increases in local services that are needed.

But it does vary wildly - I work with a larger firm, we have in house professionals who focus 100% of their time on state and local tax / sales and use tax, various aspects of international, employee benefits, trusts, estates, gifts, etc, in addition to various industry focuses - and as a result we charge higher fees because there is a significant amount of very specialized knowledge floating around that is at our clients fingertips as they need it.