It is a good idea but not all projects are generous to share the ETH they mobilize. There are many projects they do not sell their tokens and they can not divide the ETH they mobilize. Apparently ETH is more stable than the token they release. They look for redistribution of their tokens because they do not lose anything. ETH is the source of money to help them develop the project later. Your idea is good but not really feasible.
Exactly, and there are plenty of projects to choose from. You can just pick those that are paying in ETH or Bitcoin.
No, it is not a good idea, because some bounty tokens has a great potencial for growth, and i think that the payment in Ethereum will be much less than in tokens at the price of ICO.