There are accepted ways to conduct business, you need to follow the conventional path as closely as you can to reduce changes of your entity being disregarded with sham transactions.

Disregard question.

Others will not, either out of ignorance or blatant disregard for the law.The best thing to do is to choose your desired municipality and google "[city name] short term rental ordinance" (and variants of that). 

I'm fairly certain that disregarded LLC is where I want to be, but I don't know if I can covert what I have from s-corp to disregarded, or if I should convert vs dissolve and re-create.

Not generally advisable with rental real estate.A series of single-member LLCs that have not made a corporate tax entity election are disregarded for income tax purposes -- you'll report the activities directly on your 1040 as if the LLCs don't exist.

The IRS considers single-member LLCs to be disregarded entities.

Since you are in PA, you may want to read this and disregard some of these other ideas:http://www.biggerpockets.com/forums/52/topics/72185-water-sewer-bill---what-to-do-with-it?

I am not intending to owner-occupy, although I have not completely disregarded that as an option.

@Joshua MassariIt is very rare to have a blocking C corp in a SDIRA simply because the amount of UBIT generated would have to be pretty massive to outweigh the benefits of the LLC acting as a disregarded entity for the IRA.

@George Brix, If that LLC is a disregarded entity the IRS ignores the entity and says that you are the tax payer for 1031 purposes.