@Alan DuroSo the real question is can you contribute a personal capital loss to a partnership, c Corp, trust, etc...Unfortunately the answer is no.However, among closely held entities, I have seen partnerships stuff gains into non taxable partners or entities with loss carry forwards such as your friend has.

I know that it is important for liability purposes to file for an LLC potentially before we even buy our first property, and I think it can help to establish in writing how we'll split profits, but I a) know that the percentage in which we will be contributing funds will change overtime and b) am a bit apprehensive about the initial costs and if it would cost us any additional amount to have this LLC filed without immediately adding properties.

What i can contribute to someone now is my time, and my work ethic.   

I decided to build a trustworthy branded business as we've always provided quality finished products, contributing to the neighborhoods we serve.We are now buying all of our houses off market and direct from sellers through various forms of (expensive) advertising (Google AdWords, radio spots) and are starting to get direct referrals from previous happy home sellers.Now that we are currently managing 7 rehabs we've faced a ton of challenges.

That being said I have my 401k which I contribute to monthly that will provide a sufficient retirement decades from now.

However, they are almost certainly contributing to your “poor credit” if they’re carrying a balance because they’re still going to factor into your overall credit utilization.

If I partnered with you with me contributing the money and you contributing the expertise and us splitting the net from the sale I would expect your sweat would be part of your contribution. 

As an owner-only business retirement plan, the Solo 401(k) has higher contribution limits, allowing you to build your savings on the front end as well as providing investment flexibility.

The "user" member has also contributed capital to purchase the property, and pays for its expenses, including property taxes, HOA fees, insurance and repairs.

Basically you are dissolving the old partnership, and contributed property to new partnership.