I thought I'd squirrel some money away in case of a big ticket item like water heater, roof, etc. 

Professional property managers are often licensed real estate brokers who specialize in acting as the filter for you for the number items, which are not only costly but a headache.

They can also be another item that will need maintenance / replacements if they break down. 

This is for mid-range quality and minimal assembly items- what you save in purchase price you will lose in replacement and assembly costs!

I just can't see a world where there isn't some tax change that happens next year to at least make some of the more procedural items of the TCJA permanent + other changes.

It would primarily be the due diligence items that would cause a snag.

My Guess is these are likely small enough items/repairs that probably weren't looked at too deeply or considered during the due diligence and inspection, which I would totally understand.

Here's some food for thought:- Many of my first time investors know from the jump that they aren't going to be driving 5 hours round trip for every little item, and also know that they arent prepared to handle things like disputes, evictions, lease violations, etc.

When you get an inspection done we send it to the builder and all items are repaired without question.  

When talking with a possible Property management company the LAST item to discuss is $, I can't stress this enough.