Easier on everyone to negotiate a move-out than to force one with eviction.Hard to read the small print in your post, but looks like you have a mix of different size units.

In the same building (~400 apts) there are less than 10 available rentals across all sizes and spotting fakes was easy. 

So there is a difference depending on the size of your inventory.

The other issue is that my HVAC guy said the AC unit (in basement) is too small (3 ton) for the 3000 sqft house per code and need to be replaced but my house inspector said the size of the A/C has more to do with design and planning. 

The thing is I don't know how I'd go about finding a buyer for it once it is under contract because of the work needed as well as its size.  

It will vary by area & asset class.Out where I am 10% monthly & 1 months rent is common.3 or 5 SFR is a very small portfolio so I would not expect to get a price break at that size.

Like anything else I guess it depends on how many lots relative to the overall size, how good the deal is otherwise, and the general characteristics of the park/lot owners.  

Assuming your bathroom is an average size (5' x 8') the additional cost of replacing maybe 4 sheets of drywall versus the labor intensive method of patching, floating and sanding the existing walls, and hoping you get a uniform finish, is a no brainer.

After reviewing many medium-sized cities, mostly near my hometown in Southern Michigan, I discovered Fort Wayne.  

Next door house 4/2 same size asking $385k.Bought a 3/2 condo in Stockton in 2014 at $70k.