I put cheapo laminate in one of my houses when it was all I could afford and even that is more appealing to tenants than carpet would be.In a studio above a garage that I have, I put Lumber Liquidators solid oak flooring but it was only 1/4" thick as I didn't want to have to reframe the entry door.

What mil thickness vapor barrier if any would I need.

You could also pull the front off, and have the entire backside growing inch-thick fuzz. 3 year vacant sounds like there is a pretty good chance of the second scenario.

The walls are very thick stone not thin. but at the price I won with the last owner putting in 200k on a new roof and boiler and remodeling one floor I will be glad if it appraises for double.

The instant the tree cracks open and begins to fall, a SWARM of bees flow out, thick enough to be seen on TV, and all hell breaks loose!

, not beat on Scott day, but that’s ok, I have thick skin!

Should I invest a ton of time and money into trying to level the floors upstairs, or should I just throw some new carpet over it with a thick pad and call it good?

I have seen commercial leases 3/4 of an inch thick on legal size paper . 

These include:door width, hight, swing direction, door thickness, center of knob from top of door, top of door to top of hinges, ... did I miss anything?

The local yard that caters to investors & flippers has monthly specials on the 3cm thick granite, which should be nearly indestructible, when compared to laminate.