The last thing I want is hundreds of thousands of dollars sitting at a variable rate loan indefinitely that I have no means of paying off. 

It would all qualify for a 1031 exchange and this would let you sell and buy new investment real estate while deferring the tax indefinitely.

They carry forward indefinitely until you have passive income to offset or you dispose of the 'activity' (i.e. the property).If you're below $150k in AGI, you may be able to use some or all of the tax loss from the rental to offset other taxable income if you can substantiate active participation."

I also find that I typically help at least one friend/family member with a transaction each year (which will cover the maintenance costs of my license indefinitely, moving forward).- Yes, there is increased liability; however, if you take earning your license seriously, it doesn't take much to understand what must be disclosed, how to disclose it, etc.

The problem with working with bad contractors is that they can delay indefinitely.

(planing on holding them for 5-10 years or indefinitely).

But yeah, we're trying to find the right property that we can live in (with 2 daughters) for about a year, which I believe is the FHA requirement, and then move out and rent it indefinitely afterwards.

And when an investor does this using 1031 they want to continue to get the benefit of deferred tax and additional income indefinitely. 

Yes, in theory you can do it indefinitely.

My totally biased, but correct opinion, is if it meets your cash flow criteria, you keep them indefinitely.