Why not look into offering a premium platform on top of the OSS offering? What is the license on the OSS software, and are you comfortable offering open sourcing something you want people to pay for?

90% of everything is crap. If your market is underserved, then you have an avenue.

I am a fan of OSS and wouldn't be particularly worried having my platform be OS, in whole or in part.

I hadn't thought of a premium platform on top of the current OSS solution, that's a really good idea and I will need to look into that a little more. Some elements are MIT, some are Apache 2.0; I haven't seen anything prohibiting commercial use but IANAL.

I'd say it somewhat depends on the quality of the people working on the open source project regularly and the track records of the VC's funding the startups - in addition to your expertise.

It is possible to consider both as a good sign that your idea is valid. There's a reason that more books on Abraham Lincoln are published each year than on Millard Filmore - the reason is a large market.

Most likely, for any awesome idea you will have, there is a high probability that there is a VC funded startup or open source project in that domain. Question is: what probelm will you solve that your VC funded or open source competitors are not ? How will you do better than your competitors ?

Depends on how in love you are with the idea. If you feel like you could own it, and really do something special with it, then do it.

However, if it's really about money - save your energy.

How similar are your ideas? Is there a chance that you could be an early employee at those companies? In order for it to be worth your time, you have to have a chance of success, and you know that the other team already has an advantage of money. If you don't think you can make it, get in touch with them and see how you can help.

You know how the saying goes: "If you can't beat 'em, join 'em."