I think you may want to start of the arrangement in a more simple fashion.Ask for a loan in which he will get a stated return 6% to 12%.If you are both successful happy with this arrangement, upgrade to a partnership.I think a partnership off the bat makes things complicated.You will also likely make more money in a loan agreement if the project does well.

Seems extremely high but maybe it’s typical? 

I found the spreads on the fix and flip projects were only 50k - 70k because the initial purchase was high. 

With high interest rates, there's less competition and more stable prices.

Unlike common mindset, the value add should be in high cost market to achieve highest return.

And it's good that you can always return to long-term or mid-term rentals if need be. 

A high yield savings is a good start. 

I wrote an entire post on how to file your tax returns that so that they are more friendly to lenders you can read HERE. 

She boldly claimed, "If you think gas prices are high now, just wait until you're forced to drive an electric vehicle,"I, like many others, doubt she has actually driven an EV let alone charged one.

I am considered a high earner and in the top tax bracket currently.