Hi Scott,
1) I think a DSCR is a great option. Many lenders have pretty strict underwriting guidelines when it comes to short-term rentals that drastically inhibit short-term rental acquisitions, but some can allow you to use AirDNA Projections to underwrite your deal. I suggest looking on the BiggerPockets "Find a lender" page to find a good DSCR lender who can finance with AirDNA.
2) Typically I look for something with dwelling coverage equal to the replacement cost of the property and 6-month loss of rent coverage, but honestly the best coverage is whatever makes you sleep the best at night knowing your asset is safe. Insurance is always the first line of defense when it comes to asset protection.
3) I would suggest purchasing the property in an entity. I suggest getting a Texas LLC and nesting it under a Wyoming or Delaware LLC. An entity in the state of the property is always the first line of defense when it comes to lawsuits, etc., but having it nested in a state with good anonymity provision is a great way to keep you from getting a lawsuit to begin with (because they don't know who to file against). I know DSCR lenders can lend to entities whereas conventional lenders cannot.
4) I would make sure to have something with that "wow" factor on your property. Anyone can toss up their house on Airbnb, but the pros manage to charge above-market rent because their rental has that extra "wow" factor that makes the property feel more like a resort than just someone's house.