Like I said, I am in new waters here, and want to make sure that I cover all bases , and do things the right way , as to avoid any hiccups come Tax time

They are one of the "Big Three" – alongside contracts for deed and lease-purchases – all of which are creative devices for getting less than fully-qualified buyers into a home immediately.

Find an all in one or one stop shop service whose mission aligns with your goals and who can provide you with services to assist you versus just products to sell you and who ultimately empowers you by coming along side of you as you begin this great journey of real estate investing.

You could run into hiccups with DTI ratios, etc. and - worst case - by not disclosing you're committing (unintentional) fraud.

I have never seen a property that has exhausted all possible appreciation forcing opportunities so even if it seems stable it might still have some "meat on the bone" to improve income or reduce expenses (e.g 100% occupied property usually means there is some room to increase rents).Lastly, forcing appreciation might sounds like an awesome thing to do but it involves a lot of hard work, careful planning and being ready for the hiccups and surprises life throws at you. 

Maybe one of the partners has a life-hiccup and you want to buy him/her out of their share.  

You now have one pool of self-directed funds that can be invested with checkbook control.The Solo 401k cannot invest alongside you personally or your LLC - that would create self-dealing issues.The Solo 401k could flip houses, but you would need to hire contractors and remain at arm's length.  

If there's even a small hiccup in the market you will be lucky to break even, but will probably lose money after expenses.

Every deal is a little different, so the more deal variations and hiccups we see the more us newbies can learn.

What's BEST is if investor 1 puts up money/time alongside me, we get the remaining 10k in outstanding issues cleared up and sell the house for 250k by listing it in the next few weeks.