Do what you love. That's all that really matters.

Ask employees about their schedules, not HR folks. Catch them outside of the formal interview if you can. You'll know if things are really flexible.

I wouldn't count on not working full time unless you're a contractor declared to be part time.

If you can't get funding to go full time on your own project, nights and weekends with a day job provide a pretty good amount of time.

Don't get a job that requires skills in MS tools. Period.

I suggest waiting and seeing if you get into YC but in case you don't and you still need to eat (I like to eat too) then I would suggest looking on Craiglist for a job.

If they really like you ask to see if you can work 3 weeks a month and take 1 week to work on your project in there office on there computer, that way you are there available to them but they don't have to pay you.

That is what I am doing and if I get into YC I will be in a position to quit entirely and only work on my project.

If I do get into YC, I still have three months of expenses until the winter. I don't have to funds to coast, and I don't want to put my project on hold, either.

I forgot about the 3 months, at least do something that hones your skills. Anything that makes you better will be worth the time plus you will make some extra money.

How about doing some consulting for a startup, maybe even one from a previous YC round? You should be able to negotiate a pretty flexible schedule if you have expertise they need.

I've started out looking to do just that. I'm amazed by how bright and receptive these people are. It's a breath of fresh air.