Try to keep cool/neat/unique things in the park that millennial's would like, for example, maintained playground for kids, muscle beach style outdoor workout area for adults, a neat trail system inside the park itself for dog walkers, a community BBQ area, etc...

There is nothing wrong with that though some people have a more flexible criteria or larger "risk muscles" so to speak.

But, I saved a few G's, so that's easing my aching muscles.

Wouldn't surprise me, if this realtor was a friend or relative, that's trying to help out and flexing his muscle. 

Execicse some financial muscle and Pay off the student loan in three months.  

However, I'd like to flex my creative financing muscle and save a good chunk of my own cash if possible.

When you define the expectation to a creative then you are assuming permission to say “this does not work”  when you have a stager that is going to get photos for marketing out of the deal they will stretch their  creative muscle sometimes accidentally not working in the best interest. 

Off the top of my head I am thinking:Me (the brains) : 40%,Contractor (the muscle): 20% (since he will be paid throughout the construction phase, and then 20% of profits after home sold)Rich Friend(The Cash): 40% since he will be providing all the money for the deal)

It's not as cool-looking as its brother the GS850G but still technically qualifies as a muscle bike.

Sounds like a great learning experience, as well as practice exercising that risk muscle.