The costs associated with managing properties are well established for anyone investing.

Say I met with him and i referred you.Also, he does "double closing" which means he will provide you the funds to do it but obviously it will cost you a %.

depends on the remediation cost and if the budget can afford it 

As mentioned above, you could go for STR loophole and try to offset your tax liability with deprecation created via cost segragation 

That lien needs to be added to the cost of any refi, and changes the calculation when or if a refi makes sense.

As you continue to grow you'll thank yourself later that you prioritized bookkeeping because playing catch up can be difficult and costly. 

So the cost to turn this into a living space might be exorbitant.....check this out with a GC and/or Engineer before you go too far down this road....

BUT, it all can still lead to major cost and time problems if the borrower files for bankruptcy protection.

Incentivize their utility costs and construction.

Same for backyard - even if it's small, cutting it in half with a fence makes it easier for both to enjoy a holiday barbecue in their own space.These are low-cost options that will help create a better relationship with tenants.