You should know how to change a fill valve in a toilet, replace a ceiling light fixture, replace a ballast, balance a ceiling fan, replace a hot water tank, change the agitator dogs in a clothes washer, replace a heating element or thermostat in a dryer, etc. 

keep a damp rag nearby Minimize extra work.

Why do you think a clothing store stocks pants in standard sizes?

Yesterday I went to the house and there were clothes and boxes inside the house. 

I had a tenant ask to install their own clothes washer because the husband was a mechanic and they wanted something heavy duty.

Guess my question is....so you supply a completely empty unit that was professionally cleaned...and the owner gets bed bugs.....which are typically associated with..... beds, clothing, etc etc......so who is ultimately responsible?

Walk down the steps to the basement , a foot of water clothes , trash and soaked furniture . 

This pre-tax 401(k) money will either be hit with a 40% loss now, or it will be hit by (what I assume will be) an even bigger loss in the future as taxes to rise to feed, clothe, house, and bomb the rest of the world.I also don't believe it is fair to say I am missing out on market gains.  

elbow grease and a damp (non-metallic) scouring pad

I use to own some Laundromats and know first hand how they get abused.  50 pounds of clothes in a 18 pound top loader!