I have degrees in Mechanical Engineering and Physics and I have a full time position in field service engineering.

I guess is what I am looking for is a program or chart that shows the standard time frame to clean a unit, kind of like car mechanics use when doing car repair, there is set time that is set to accomplish each task so it is far for everyone.ThanksKevin 

I had tenants paid me in cash, heard stories of Landlords paid in cash leading to problems and I myself ran into problems with people paying me in cash.I had a auto mechanic who told me he gets paid in cash and would like to pay me in cash.

A little bent sheet metal wasn't my concern bur how bad the internal mechanics could be damaged.

Most landlords have periodic inspections of the interior of the units built into the leases to check for cleanliness issues, water leaks, mechanical systems,etc.Expecting tenants to change lights, change air filters, make sure connections are properly hooked up is a long shot especially the further you go down the tenant quality ladder.

Very nice renovation with all new major mechanicals and interiors including laundry in each.  

Installing all new mechanicals hardwood, 2 bathrooms with low-mid finishes, batt insulation, $5k kitchen plus granite, new appliances, misc framing changes and a foundation repair.

Perhaps even tampering with the house mechanicals. 

Fear is not always a negative thing, as it’s a mechanism used to keep us from doing things that harm ourselves.

Check craigslist.org for the cheap ones and the appliance repair guys for their scratch and dents, like Michael said.I also agree with Jonna that you should develop a relationship with a few local "mechanically talented" guys you can have on call in your cell phone to call them up and say "This is what happened, can you fix it or do you know a guy who can?".