Things change daily in a start up. People come and go in the market all the time. That's expected and YC is not going to accept or deny you based on a new competitor. In fact, it will look good that competitors are coming into your market. Besides, YC is more concerned about the team over the actual product.
This is an excellent idea! I see this a lot more lately and I prefer to work on different projects to keep my talents fresh as someone else mentioned. I also like working in different environments because as you mentioned, it is difficult to get a feel for a team in just 4 hours. In the traditional job environment, you often find that the team isn't a fit until its too late. Your arrangement is great for all parties. However, the employer doesn't have a lot of incentive to invest in part-timers or moonlighters and there is less of an incentive on the employee to make the start up their life as is necessary in a lean and young company.
We are all facing this problem. I agree with Steve that it is like finding a spouse. I saw a list of co-founder sites on Quora and posted to them but I'm not pleased with the responses. I'd love to talk you! I have an MVP, users, integration partners and the beginnings of convos with investors. Totally looking for a co-founder. Let me know if you'd like to chat.
