For me I can troubleshoot furnace issues but if I have a tech come in and tell me the repair will cost a couple hundred bucks I'm replacing an older furnace o a more efficient model every time. 

The court just awards an actual cost as you are out $10 the award is $10.The HOA and COA's aren't regulated with the Move In/Out Fee and don't charge an actual cost amount. 

Their paint is thicker thus why it cost a little bit more.

I sold it two years after I bought it and vowed to never deal with a HOA again in my life.They're a pain, and they're an unknown future cost, as well as unknown future rules. 

Also included is interest lost due to that money not being in my bank (general interest i think they call it) My time being the most costly and rightfully applied to the cost as I am working for my company and I don't work for free.

A new gas stove usually runs just the $300 to $400 you stated, so teeing off the existing line, adding a shut off for the stove, and piping the stove will all cost a bit more.

Your biggest cost, as long as you act reasonably, would be a rent abatement for days your tenant can't use a property. 

Truck would be useful if you need to haul things but cost a lot extra in unnecessary gas money if you don't.

There may be some units that will cost a lot of money to get market-ready and keeping a long-term below market tenant may be more cost effective for the time being.  

(It will cost as much as new construction)  Either way the ADU route could be a good option.