Also <most times> adding a extra bedroom but not adding sq ft doesn’t help much on ARV specially currently being under 1,500sq ft.

The issue than became adding utilities. 

My question is if we are marketing this as land, is more value added from the 2020 mobile home or the multiple utility hook ups?

Ironically its the investors in the layered LLC's who believe they are hidden in the cloaks of secrecy and better protected who end up in  the most costly and drawn out litigation while giving the plaintiff attorneys reason to take a more thorough look under the hood.Keep your LLC ownership simple, carry appropriate insurance, make sure ever vendor you work with carries appropriate insurance and those who perform work functions most likely to lead to liability exposure list you ad additional insured (not merely certificate holder) and it should go without saying, avoid negligent conduct.

A capital improvement is not - it gets added to the basis which ultimately reduces the tax due on sale but it’s not tax deductible in the sense in reduces current income. 

So as an example, if the hose sells for 90% of market value then it is doubtful you will get an added 20% on the table with your discount.

I plan on saving all the letters and calling them to be added to their buyers list.

A good example of this might show high return for a house in Detroit that is 100 years old, next to a GM plant, vs lower return for a 10 year old house next to the Tesla plant in Taylor, TX.   

I just don't like to see the government adding all the regulations and significant costs (those systems aren't cheap) as a knee jerk reaction to tragedies. 

And the added cost of the ventilation systems needed to deal with an indoor pool.