Put them on the lease pending a favorable background and credit check.

Of course, you want to pay attention to where you have the more favorable interest rate, though, before you do that.Regarding the "waiting period", that varies from lender to lender.

I got it last year at tax lien auction for cheap as a favor for someone, but I have no clear path for it

Do yourself a favor and get with a seasoned investor to whom you can bring potential deals for evaluation and then shadow him/her so you can learn how to do real estate investing legally and ethically.

As far as screening lenders, it's important to know how many deals they've done, what kind of deals they favor and what kind of deals they don't do!

This type of loan isn't looked favorably on by sellers. 

I’m sure the split won’t favor me, and that is okay.

This usually makes the marketability of the properties less attractive.It is generally not advised to try to assume a lease from a tenant especially if your state has favorable tenant laws. 

Chance favors the prepared, I guess?

This means after analyzing and initial due diligence, if your numbers worked even if you made an higher offer, make the high offer to fend off competition considering the terms and numbers are favorable.