I sell with dual license in KS and MO, but want to do more.HiA great start is putting a deadline to that goal you gave yourself.We can assist by holding you accountable , encouraging you along the way.To hold that many properties, equity is your target....Alot of free equity.You can get that as you help motivated sellers solve their problems too 

The owner of the unit above me has been extremely uncommunicative - she was pretty averse to any sort of mitigation action as her HO-6 adjuster told her as long as she dried up the water herself she was "all set", despite my telling her that her subfloor was obviously waterlogged and moldy.

Are there lenders that would actually let us do this and if so what sort of criteria would need to be met?

That does not yield any sort of return. 

I think its sort of obvious:Whatever sfh your buy for yourselves, you need to get it low enough to pull out enough cash for your next deal. 

This was a live in flip, sort of.... my husband lived there when we met.

How would you approach a seller with this sort of proposition?

Assuming the income generated flows to your schedule E and gets sorted out in the end it may not matter. 

Look for motivated sellers and distressed properties.

What strategies have you used to motivate tenants to quit the lease and move on?