If they are a trade they may go to a smaller town since we seem to have a state wide building boom.

You will probably be better served picking one location and knowing it well rather than using a wide net of locations till you get some deals under your belt.

Rates well vary widely depending on credit and down payment amount.

I looked at a used stackable W/D set, 24" wide model, which will fit just right in the laundry closet, for $400 with delivery, or $525 with 1 year warranty.

However, I want a nicer trailer and not a 1972 single-wide!

I don't know how large your condo complex is, but for condos of 50 or more units, it would be a challenge to get every owner to get to it, and properly clean the vents if it was discovered  vents were never cleaned and it could be a safety hazard.I also had special assessments for new roofs, other building wide improvements at my rental condos. 

I take the arbitrage loss as a trade off for emotional ease and I do it with my eyes wide open.If your eyes are open then there's absolutely nothing wrong with spending $226 per month to "buy emotional ease!"  

That answer varies widely.

There's no perfect answer, because it will vary widely by location and the actual property. 16%-18% pre-tax profit (of sales price) is a pretty good rule of thumb.

Start with some reading here: http://rapwp.oaklandnet.com/ Craigslist and Facebook are used widely here for rentals.