Armence

On the Linux on a laptop issue, I'm pretty sure there is an EU Consumer Protection directive that prohibits bundling software with hardware except in cases which are irrelevant to your situation. So you should be able to buy a laptop and then get a refund for the M$ software on it.

I'm pretty sure that you can't throw away your Section 2870 rights. But then again, I would consider it less than honest to sign an agreement with the intention to challenge it if it were enforced. Also, not legal advice.

You should explain to him that you are just as capable as he is to take legal action which would put a nice big hole through his funding possibilities. Then, offer to either sign something that says you owe each other nothing and that you are free to do as you wish with the code you wrote. Or, tell him he can pay you to sign the NDA. If your product is good, it's probably not because of the idea. It's probably because of the execution. If he is willing to pay you enough so you can spend 1200 hours on a new product idea. Go for it.

The primary problem with this situation is that this kind of fee comes as a surprise. If the fee was known, you would demand a lower price for the property and the realtor would take some of the additional valuation when the property got sold. Sounds familiar? It should. That's basically a stock sale.