If you are going to take lower income in exchange for increased risk, why take that risk with someone like Marcello? Why not find a talented PM and biz guy and come up with your own product idea?
Depends on the state. Microsoft in Washington has non-compete which can get in the way. If you are only looking at IP restrictions, those are weak and difficult to enforce. It's really there to keep the dev from suing the BigCo for personal IP that leaked into BigCo's code base.
On the other hand, would you ever go work for a company that went after a small entrepreneur for some minor breach? They'll scare all the smart code monkeys away.