If I try to pursue the furnished LTR I will definitely keep this in mind that it's possible I'll be starting over again!

small portion" of profit is not worth the possible legal issues.

There is realized gains & profits, and UN-realized gains and profits.

To get things done as quick as possible , charging by the hour cost the contractor money , charging by the push/inch  is the most profitable way to do snow . 

Our recent fund was a preferred return plus a split on profit after expenses.

Like @Kyle Mccaw noted there is significant value in goodwill and I imagine you profited nicely over this pleasant long term relationship. 

Additionally, keep in mind if you do this in a Roth then there are NO taxes on the appreciation, rental income or profits when the Roth liquidates the asset. 

As I studied earlier, the first thing you should do is marketing, then get a call and do a property analysis to understand if it's profitable for you, then meet with the seller and sign all the necessary papers, then if there is a debt in the bank we do a reinstatement quote, then do a title search to check if there are any hidden debts, if everything is fine we look for an investor or flipper and sign an assignment of contract with him and wait for closing to get our money.

When you live in that duplex for 2 years and then sell you'll be able to take 50% of the profit tax free (the allocation for the side you lived in). 

Sometimes making a smaller profit and providing value is far better than holding out for a bigger payday on a bad deal, I like that.