If it is April 1 I might hold the application and see who else applies.

It seems like a lot of information that does not apply to me ?

At the end of 5 years, you can decide to change lenders, in which case you need to apply to other lenders, or your existing lender (as long as you have been making regular payments) will offer to continue your loan into a new term with the existing amortization continuing.

Or do the notice rules only apply to entering the actual house or apartment?

Secondly, DON'T apply for such over-leverage!

Apply for at least 3 cards and stop there.

Although I plan to learn more and apply various investing strategies (wholesaling, foreclosure, rehabbing, etc.), I am most specifically interested in multi-family properties (duplexes, apartment communities, etc.).  

I hope it's not too late to invoke the partner aspect, it allows you to be a lot more demanding in terms of your due diligence, and it allows you to not be the bad guy if you have to turn them down ("I wish I could have helped you but my partner said no and we can't invest any of our money unless we both approve the investment").To your original question, IF you decided to make a loan like this, I would see three options:Unsecured personal loan (weakest/worst/don't do it option)Secured loan - they buy property and you are the lender secured by a mortgage on property (better)Rent-to-own - you buy property and they rent from you with an option to buy (questionable esp w/ family, may be tricky or illegal depending on how structured, etc. and see next point re: owner-occupied)However another aspect is that since this would be an owner-occupied property, there are a ton of consumer protection laws (Dodd-Frank) that apply.

So as pointed out, what works/and is recommended in one state may not apply at all in NJ.Also, if you can afford to put each property into a separate LLC that's great but I agree that even if you can it may be overkill.

I found a bunch on meetup.com; not sure if that'll apply in your area.