It's really just an opinion question, either case could work out really well or bad.

Different lenders have different preferences, so it's whatever you work out with them.If you're not able to pay them back on time, you can sell the property, ask the lender for a loan extension, or otherwise re-negotiate.

If the numbers work out, and are real numbers, there's no reason not to do it.

🌪️🌊🌪️🌊🌪️🌊 This over-assimilation of knowledge may also be creating a mirage of "I know a ton so things should work out", which can then cause result in this gradual, but effective, fatigue when "things don't actually work". 

The neighborhood is booming and its great investment but it needs intensive rehab.

I had looked into their program but I thought it was costly based on my business model as I do some of the workouts etc.

Builders won't give you a deal because you're an investor; to them you're simply another customer - likely one who's more concerned about price than anything else.You might be able to work out a deal where the builder shares in the profits at sale in exchange for a lower margin on the construction, or some other funky profit-sharing arrangement, but I wouldn't lead with that offer unless it's an especially juicy deal.I'd start by hiring a guy you feel comfortable with and then building a relationship.

I’d consider managing it for you, and even if that doesn’t work out I have pretty good contacts for cleaning and for furnishing units.  

Plus it sounds like you have your ducks in a row and unlike some many other splits, besides an up tick in costs that you currently split, yours should work out quite favorably.Finally, I would do the book exercise that @Daniel Donadio Jr and look at the relationship through the framework that @Ola Dantis laid out.

I have tons of friends that buy a new rental where ever they move and just make sure the numbers work out.