My take is that if you know this is what you want to do, do it!! I have known that I wanted to go for a phd in the humanities since my first year of college, and I spent my whole college career working towards that goal, so when senior year came, I did it. It was a lot, but grad school application is a lot regardless. I am glad that I did it, though.
I got into more than half of the schools that I applied for and have committed to one of my top choices. I don't think applying as a current undergrad hurt your chances, as long as you can demonstrate that you are passionate, prepared and committed (which i mean it's the case for everyone).