Companies are in business to make money for THEMSELVES. That is neither good nor bad, just a fact. And that non-compete document sounds like a lot more than that to me. I would tread lightly with them if you need the job.
One suggestion would be that if you are going to approach them with a product idea or invention, try to find one that you may not feel is very valuable or easy to market. In other words, one that you don't mind giving to them. And see how they react to that. Then, if they are OK with that one, somewhat later, like two or three months, try with one that is a little better. See if it is still just as easy to get them to go along. This will give you a toe in the waters to test them.
If you have any difficulties with those initial steps, perhaps consult with a good, local attorney.