I noticed that those that sat on market in less time and had sold for the target price also had favorable performance against indices mentioned.

Do yourself a favor and align yourself with a licensed MH dealer who sells used homes. 

Other thing in your favor may be the detached building.Now the first deal is probably slightly better.

You’ll get your full security deposit back as long as everything is left as it was when you moved in”You’re doing HER a favor and not making her stay in that dump of a house (I’m obviously joking - but making a point that she gets off easy).

Maybe if you have some sort of favorable promote structure with an equity partner. 

If you use the listing agent, their duties will still somewhat favor the seller whom they have a longer relationship with essentially, so why not find your own representation?

It’s a huge tourist market, it’s near the beach, it’s drivable to a large portion of the US and the laws are favorable.

Our concern is two-fold (1) it may be difficult to get a loan given that both of us would be considered contractors and I know banks wouldn't look favorably on that, and (2) just the overall fact that both of our incomes would be commission-based.  

If you go that route, do yourself a favor and do not shop it around yourself.

While the numbers may not be favorable for some, the important part is that you guys took action and the deal is working for you.