There are a lot of factors, but in general yes a small MHP is a good way to cut your teeth on the segment and get your head around all the aspects.  

So I am wondering, short of ripping it out and putting in a new insert, are there some enamel paints or other coatings that I can apply that are "good enough"?

Look for cheaper properties to cut your teeth on that have better margins.

My goal is to one day get into the big multi units like you have just described, but since I am just starting out, I figure its best to cut my teeth in something a little smaller.  

VA funding does kick you in the teeth for the second, but if you did your math correctly, it shouldn't be a problem.Another bit of advice.

Getting your teeth knocked in a couple of times really makes you change your definition of "acceptable risk."

It was like pulling teeth to get them to go over after a vacancy to assess.

I can see how getting kicked in the teeth by the judicial system could quickly create a motivated seller. 

If you imagine a property's income to expense ratio to look like the teeth of a handsaw, either pointed up or down (depending on your market), you want to select the tips of the points for consideration of where/when to sell.If your sawtooth is pointed perpetually upward - i.e. a rapidly growing area where property values and rents are increasing faster than the house is deteriorating - you might keep it "forever", or for a very long time, as each sawtooth tip will be higher than the previous.

It costs you nothing to sign, and there's not a ton of teeth behind it -- mine basically says that you'd be willing to pay my fee if for some reason a FSBO won't (hasn't happened to me yet), and that you'll actually terminate the relationship in writing instead of using the skills of the agent and then ghosting them.  100% of my buyers sign one -- it also authorizes my to act as a single agent, give them full confidentiality and disclosure (not the default in my state), and negotiate on their behalf.