I was the first person to partner with them. 

I dont like any company personally that does not put their principals on their website as in meet the team.. ... 

In theory, you could QT the property to an LLC in your name and enter into a lease with you personally.

Definitely a personal preference.

Lenders often include a portion of the cash flow in the investment property as income to you personally to offset the DTI. 

I find it's very personal, and dependent a lot on your goals, resources, risk tolerance, location, experience, etc.

I can't just put the LLC's income directly into my joint personal tax return, right?

I 100% agree with the intent aspect and that is an important premise, but the fact is in this particular situation intent for it to be personal use has been confirmed (by way of a public post).

The other PM can be a fix-mindset type of person where they are not willing to share anything unless you have a property and are willing to sign a PM agreement in the same conversation. 

Rentals are extremely difficult to make pencil right now but would only personally consider higher end projects because the costs are far easier to absorb than trying to build in lower value neighborhoods.