He left our property in dismay for months and charged us a Change Order for demo work but could not be bothered to clean up after himself. 

If, on Monday, I were to put a contract on a property that I knew I could sell immediately, and if I had the cash to close, then the only other thing I'd need was clean title, which takes my closing attorney about 3 days.

If I were a betting man, I’d guess that opex would be closer to 50% given a lot of expenses are fixed (lock change, carpet cleaning, owner paid utilities, appliance repair, just to name a few) regardless of a unit renting for $500/month or $800/month.

Another option is going the turnkey route, where although you will be a long-distance landlord your level of involvement will still be minimal, as the turnkey company and the property manager handle most of the daily hassles. 

Empathize with Bill and the seller's position and suggest that if you can't get back the funds you at least want to help the seller's case in court, work out some sort of deal, talk about a master lease option, basically anything that does not involve the idea of litigation. 

I am moving towards putting up curtain rods and inexpensive curtains though- I feel they hold up better, I can wash them (if the tenant didn't) rather than dealing with the utter pain it is to clean miniblinds, tenants seem to like them better, and they look a whole lot nicer. 

I'm a believer in clean and updated kitchens attracting better tenants and buyers, so I find good appliances to be worth it. 

No, just 25 yrs of experience being involved in literally thousands of deals and watching realtors do things the wrong way or take shortcuts, loosing deal after deal for my borrowers is what has taught me what works best.Unfortunately, down here in FL, everybody and their mother has had or has a real estate lic. and too many think or lead their clients to think they know a lot more than they really do. 

A flip is just like cleaning up after a really bad tennant lol 

I recommend talking to a ranger about their maintenance as it may be more involved than you think.