I'd say sure, I'll take that $ if I stil retain my 5%. 

I don't see an advantage to retaining a realtor to sell the home for full commission.

Finding out what market rents are in the area will quickly reveal if retaining the property as a rental even makes sense. 

Density is your friend, but seek out how to best do it to create a desirable place, minimize you utility/road costs, and retain value throughout the development stages (if phased).  

I've retained a team to help me handle tax structuring. 

I would prefer, personally, to invest a substantially lessor amount to fix the property to give the option of either retaining it as a rental and/or selling it without the loss or a much lessor one. 

I’d need to borrow about 50% of the value of my current home to fund the remainder of the price of the new home, and would retain the current home as a rental.

Instead of denying them, can we refer them directly over to the owner for them to sign a lease with the owner who is willing to effectively manage the contract, payment and relationship BUT would still want to retain us (albeit for a lower fee) to deliver ONLY guest and property care activities (guest communications, organizing cleaning, lawn and pool care etc). 

The seller retains the mortgage on the home, wrapping the buyer’s loan into the existing mortgage.

It's damn very facsinating and good for us the investor, but same time is also signaling, hot = good time to sell ; and to re-assess.