With the price of properties increasing it's difficult to see significant cash flow for most of the investors I am working with. 

STR can be more profitable if you set it up right with your pricing and have a balance of making your place look nice, while not spending too much on your setup.

You definitely have some options, if you do a more conventional second you can get very reasonable rates, maybe check in with you current bank or credit union? 

Approaching the end of my first BRRRR (rehab to be done in 2 weeks) and I'd like to reward my contractor with a cash bonus; I'm wondering what an appropriate amount of money is to give him. Percent of the rehab amount...

Great appreciation over here for multiple reasons

If you are going solely based off price, I would go with mojo dialer.

Owners mistakenly ASSUME all PMCs offer the exact SAME SERVICES and PERFORM those services EXACTLY THE SAME WAY, so price is the only differentiator – so, they often select the first PMC they call or that calls them back!

as the neighbor would retain some value in the land (easement for drain field) and the land is essentially un-developable, what is a fair price range?  

He will owe taxes on the net selling price minus his original cost basis, plus up to 25% depreciation recapture on about 72% of the property’s structure value. 

Purchase price: $175,000 Cash invested: $43,750 Under market purchase.