I am not personally a proponent as I think there are a number of potential issues and limitations of DIY, but you can make your own determination.

Manage the property effectively: Take care of maintenance issues promptly and communicate effectively with your tenants to ensure a smooth rental experience.5.

My biggest issue is not knowing what market would be the wisest to get into.

I have recently been running into the issue of having investors go out to a deal with interest and then talking themselves out of the deal on the way home.If you have run into this issue before as well and have overcome it, what are some good strategies to secure the deal before leaving the driveway? 

However, it turns out there was a previous offer that fell through due to a septic tank issue.

The issue is that there are pockets of restrictions all around Lake Hamilton so it would pay to have a local agent right away who is familiar with the STR market around there.Hot Springs National Park has around 2m visitors a year so that will be a big draw.Crime is on the higher side vs other areas of the country, but that is pure statistics.

That was not a great answer to your actual question, but those are the big issues with vac efficiency out side of the unit and the duct work itself.  

If you get a restoration company to come in and get all the issues remediated, and they sign off on it, then I don't see how you could be liable if something happened in the future as a result of the fire damage. 

Unfortunately mine are note based and specific to our asset class and brand, otherwise I would have no issues sharing

Based on what you have said here, it seems like your A/C damaged them, and asking for payment to be made whole seems righteous.If you pay, talk to an attorney to make sure its a one time shot, and that one payment settles the issue 100% forever, so they will not come back for more later.Good Luck!