Quote from @AJ Wong: I've been a mortgage broker twice as long as I've been a surfer but I think the professional experience might truly be about to pay off!

You can explain that any changes to the lease must be carefully considered, as you want to maintain the original terms that protect your interests.If you decide to allow the change, you could draft an addendum stating that each tenant is responsible for their own rent.

What would be a good example of terms to use in this situation for the appraisal gap owner financing?

They focus on finding long-term tenants, and it's a win-win as less turnover is less expense for us and less work for them. 

Our priorities in terms of market is there needs to be- anticipated economic growth (lots of tech companies are moving into Columbus),- prices need to allow us to buy in all cash (400k or less, ideally up to 300k),- we want the area to be safe (when looking into places like Dayton, OH or Memphis, TN for instance it looks like all our boxes are checked on paper, numbers wise but we realized quickly there are a lot of unsafe areas and we could have the potential for problem tenants)- yearly expenses to be relatively low (i.e. we are avoiding NYC and the tri state area, California, etc. for having extremely high taxes).Is our initial analysis on the right track for Columbus?

Make sure it explicitly explains the process for termination if you are unhappy with their services, especially if they violate the terms of your agreement.3.

How long would it take to pay off? 

Consider how long this might take, then double your estimate if you really have no idea.

I just wanted to get some insight on how common it is to request mold tests prior to purchasing a property and testing for mold with long term buy and holds in this climate.Thank you in advance! 

After that, it becomes long-term capital gain.