Legal document needs to be filled out?

You might want to talk to a business law attorney to be sure everything is done correctly. Someone else may come along with some additional information for you.

 

Don't invest YOUR moola with anyone, sign anything, or give anyone your moola until you've had everything vetted by YOUR lawyer. Don't take the representations of anyone about anything until your lawyer has reviewed them in writing and advised you accordingly.

What you're thinking about requires much more than one contract or a form. Further be advised, if you get involved in this, it will also impact your overall tax picture (and your spouse's), unless you're properly insulated.

 

The law can't guarantee perfection or performance.

However, if you contractually reach an agreement, you can sue if its breached.
That said, if you sue and prevail for a breach, you'll not be guaranteed to ever collect.
Why?
The entity or person could be broke, bankrupt, or bullet proof.

If you want guarantees, and you have $500,000, keep it.
You can deposit it in a federally insured bank, credit union, or savings and loan.
If, one day, the entire US government were to default (we came close in 1929); you'd lose a so called insured investment.
The ONLY sure thing is trusting in yourself.
You probably won't let YOU down.
You can lock it in your safe, etc...
If you invest it, there is no way the law can guarantee or ensure a profit or a return on the investment.

Before you invest in anything or anyone, discuss it with your lawyer.

If you still have doubts, or possess uncertainties, just do as my dad used to say, DO NOTHING, and simply say, "NO, THANK YOU!"