You can always sell without an agent, but it could cost you more money and more importantly, money in the long run..think of it like this…maybe a strong buyers broker would’ve urged more caution with the initial purchase? 

If not, I would highly, highly recommend spending time there.

If you would have simply held on and collected rent for 72 months, you would have been up money...and that is buying at the peak right before the biggest real estate bubble in modern history.

Sometimes, charging LESS rent actually earns you MORE money in the end!

Is the reason why this is lucrative to the seller because it's money that is able to be written off as a loss? 

In growing markets I’d always recommend BRRRRs over flips if possible.You'll probably still have to keep money in the deal but it's way better than putting down the whole 20% LTV. 

Which would have kept more money in my pocket.

It sounds attractive because everyone says it is low- or no-money down, but if you don't have money to make the deal another way, you don't have much leverage to make the deal the way you are suggesting.Sub to and seller finance are shiny objects for people who want to get started in investing to make money, but have no capital.

I would be using all of my own money for both the acquisition and the rehab.Also, I would (attempt) to GC this myself to save on the rehab.

I had the pleasure of spending two weeks in Bandon on the Oregon coast last year and the weather was great.