If you’re talking in city limits you might have a permit problem because they are ridiculously annoying to work with for even regular construction, outside of city limits though, especially outside of allegheny county I assume you’d have an easier go at it. 

The lender would have had an appraiser issue a opinion of market rate rent for the apartment on your duplex so that's a start on what the rent should be.

I see investors who I have spoken with have issues with appraisals which heavily affect their loans, they have worked with certain companies that don't appraise correctly and even admit to it.

Do your best to mitigate issue before they crop up and annoy residents.Maybe create a free service, for those that are not using your management services, to come and review their STRs for safety, procedures for help etc.

Your duty to disclose is a local issue.

(Permits and installation take at least 30-60 days in Vegas, so you have about 2 months to act in an area like mine.)

There are two issues I want to point out at the jump:1) 1031 exchanges are designed for long-term investors. 

Over the last 18 months, we have done all the leg work and are near the point of having our permits approved by the city and all entitlements in place for a 12Plex.

This makes a lot of sense to me, you wouldn't want them knocking on your door 24/7 for simple issues.

What else would they have issues with if they were moving in.Will they become nightmare demanding tenants?