in the last picture with the white PVC drain lines, the floor joists don't look too great but its always hard to tell in pics but there could be some rot or pest damage there. 

If not, this is going to add stress to your marriage and your relationship to your children, and typically significantly more than most people expect.Your house is inevitably going to be damaged and changed during the time that it's a rental.

Is there a third-party company that offers Damage Protection coverage for midterm rentals?

This is the “free answer” from Google, so it’s worth what you paid for it…https://www.justanswer.com/law/80qys-live-arkansas-neighbor-....Lawyer: LawEducatorUnder the common law of property you are entitled to trim branches from any trees that are overhanging on your property but must do so by exercising reasonable care not to damage or harm the tree.

I filed a claim and my insurance company is estimating the damage currently.

Even personally holding the discussions with the tenants potentially damages YOUR outcome.Landlord Representation in SF

We figure we'll have to replace them every 3-5 years as the saltwater damages them beyond use.Gas: Weber 2-burner (It was less than $300 delivered in early 2022) -  https://www.amazon.com/gp/product/B01HID4Y7Q/Charcoal: (May not be this exact one, but it's similar)  https://www.amazon.com/Weber-741001-Original-22-Inch-Charcoa...Honestly, I don't know how much guests actually use them. 

Uneven and water damaged subfloors.

Is this something I can deduct from their security deposit if there is more damage due to them not notifying me immediately? 

Also makes allocation of apartment damage easier.