I've applied before and I remember there being character limits, but they're not showing up when I load the application. I'm working on my application now and my responses might change depending on the limits.
Try to contact dang by email at hn@ycombinator.com . They usually reply faster by mail because some thread get lost unnoticed.<p>(I think hn@ycombinator.com is the wrong account, because it's for moderation an HN and not for generic YC stuff, but I'm sure he can forward the question to the right people.)