•Charged me $500+ in "materials" and refused to provide me with receipts and just gave me a generalized itemization and charged me for debris removal when I had done it MYSELF.   

Biggest items were plumbing related (toilets, faucets) or washer/dryer or AC unit related.

Your state and local landlord/tenant laws should provide a very good template for you to follow as they will state things like how much notification to the tenant for the walk-through, how many days to return the deposit, what items can and cannot be deducted from it, itemization, etc.  

On my renovation projects I typically gut the entire building down to the studs so I am looking for really big items (e.g. foundation falling apart, pervasive insect damage,etc.). - the building had been sitting vacant for nearly a year.

You allude to some of the risk items in your post, interest carry as an example.

You and your husband will be able to review reports from a manager and have a good idea if something is out of place on billing.I would just do the numbers on a lot of deals and estimate 10% for property management and use your experience to estimate the ongoing maintenance.  50-60 minutes away isn't too bad, just not close enough that you want to go out for small items.

And, yes, some of those items should be fixed. 

Your Homeowners policy will cover the basement items but the flood may not. 

That way adding a few grab bars and other items won't overwhelm you as much. 

This is the one item I’ve been searching for as I am on the border of investing into real estate but with the yield curve forecast have been nervous.