Daily word count....limit?

Agreed!

I think this is a very individual thing and you are going to need to experiment a bit to figure out what works to keep you at max productivity. Some writers do best by only writing on the weekend so they have long hours to write at one time. Some do best with a regular schedule. I think you should try something different every two weeks and write down how it went in a journal.

I wish I wrote enough to put limits on how much I write. That said, I generally write until I've written at least 1000 words and like to stop with more to write, so that when I start again I don't start stuck and can keep the ball rolling.