You should be able to get rid of that sign up fee of 3k and have only the monthly charge.

They do free sign up with 100 free credits so you can try them out.

That's a good idea too, or a personal guarantee potentially if they signing as an LLC. 

They signed an initial one year lease but have opted to go month to month ever since. 

For example, the signs of the 2008 housing crash were all over for everyone to see but many investors were blindsided by their "following the herd until the last minute before the party ends" kind of strategy and lost everything as a result.

Look for things like whether the windows are new or old, if the property is boarded up, and any signs of structural issues. 

I've managed this home for 15 years and it has no signs of movement, as confirmed by the engineer, but the sellers accepted the offer because the home is fully paid for and they just want to walk away.

You can do this with a simple, one-page addendum, or even a written statement added to the existing lease and signed by you and the tenant.Example:This lease agreement is hereby amended to reflect the change in ownership of the rental property located at 123 Straight Street, Cody, WY 82414.

How soon will you have a signed lease after you're finished with reno?

Quote from @Nelson Badillo: Quote from @Tim Delaney: In my area the agencies that manage the vouchers won’t do an inspection until you have signed a lease with the tenant.