This makes you passive and makes the income passive, which allows it to be used to offset your suspended passive losses.You can invest in an LLC, a partnership, S-Corp, or sole proprietorship.

I have some questions related to structuring the partnership for anyone who has experience doing this.

Or full-on partnership in everything I do in REI, I guess. 

I did not know how to build relationships to get the answers/help/partnerships i needed.Next tier, creativity with producing equity for deals.

That would be a strategic partnership where you didn't have to pay for marketing and you didn't have to do all the calls yourself either. 

Sure.Owner financing, Subject To, Wrap, Land Contract, (since you are in Texas Not "Lease Option"), Owner carry back, Joint partnership with the seller, VA loans.

Why not just take your 3 SDIRAs and each of invest DIRECTLY with them into a partnership/LLC?

The only way you would pay for the privilege is if you were looking to gain experience and who would want someone inexperienced doing due diligence for them2) In order to stay within SEC regulations when raising capital you typically need to be part of the general partnership so I would recommend checking with a SEC lawyer to ensure that your friend isn’t in breach of any SEC reg’s When raising capital for someone else.

The benefits after that could be stronger... if your father-in-law is a high yielding business man it could lead to private loans and lucrative partnerships and help ramp your business.

If your LLC elected to be S-corp, when the revocation becomes effective, the LLC will be treated as a C corporation unless it files Form 8832 (Entity Classification Election) to be taxed as a partnership or disregarded entity.