Before I joined the Army I did home improvement side jobs, i.e. paint, dry wall, tile, carpeting, roofing, little bit of framing, pressure washing, junk removal, lawn care.

Since then, I removed my phone number from my BP profile because I don't have time or inclination to field these types of calls.  

I think they should be included, because, like someone else pointed out, you could have damage to the floors, etc, with install/removal.

Don't forget snow removal + landscaping as well.

I also understand that value appreciation also plays into it, but I'm removing assumptions about appreciation and just looking at a cash-flow point of view.Is this just a matter of not finding a good enough deal yet or perhaps the market conditions are just not that great for buy-to-let?

You are correct that if it is left undisturbed there is no harmful effect,  where the issues occur is when removing them or if the are broken and the dust gets into the air. 

Also, as far as paying it down faster, I'm not concerned so much with having equity to borrow against as I am with just getting to 80% LTV so I can refinance to conventional, remove PMI and find another property to get an FHA on!

Could the cracks just be filled in, instead of removing/reattaching new drywall pieces?

Furthermore, there are lists you can get put on, that you don't get removed from, even after seven years have passed. 

Sometimes the home gets removed altogether from being auctioned off before the next date comes up, and sometimes it finally gets sold.The lower end deals are much more difficult to win, because of course, everyone is looking to purchase on the lower end.