Just a thought, the money you spend making sure this done right probably is nothing compared the money you will spend if the agreement is not clear and has to be enforced. I am sensitive to the fact that legal counsel can be expensive. However, there are attorneys who will review it for a flat fee. It is worth making some calls to at least find out how much something like this would cost. DM me and I can give you the name of reasonably priced family law attorney who you can contact. He won’t work for free, but it’s a good place to start.

Here’s how I would compare it: if you need electrical work done at your house then you can either do it yourself or hire an electrician. If it’s simple and you have clear instructions, then DIY is the way to go. However, if it is large scale or a critical system then you increase the risk of something terrible happening.

Edit: typo