Not sure if you can run a steam gas boiler but I think you would have to run ducts.

You might be able to change the color by reglazing with out ripping out and replacing.

I would also be adding two tank less gas water heaters.One unit is about 1000 square feet, 1 bedroom.One unit is bigger with 3 bedrooms, large kitchen and a living room.My question is with the mini ducts, how are they able to keep bedrooms warm/cool with the doors closed?

Maybe if the tenants do not like the carpet color they will be more inclined to accept a tenant buy out.I will provide two examples but my non-rent controlled example will be San Diego market (not LA) because I know the San Diego market better and therefore already know the aver rent increase of a San Diego SFR. 

Here is a breakdown: full kitchen remodel, new heater/AC unit/ducting, all the sheetrock in the ceiling was replaced (bad roof had caused leaking, so it was easier to replace it all),  new lightng throughout (can-styled LED lights), ceiling fans, and some other electrical work, painted interior/exterior, and tuck/pointing to a few areas of the brick facade.

Color has been a moving target IMO.

Like paint colors and other material type stuff. 

In the future I would like to be able to use products across residences, I plan to paint all future units in the same color schemes and so forth.

They are the colored squares.  

It's an old row/townhouse in B class neighborhood and it has duct for heating system so I have an option to add central A/C to existing heating system.