Thank you! I mostly used the first two brushes listed here [link] (it's a great brush pack if you don't have it already!) The sizes vary, and the opacity I just set to 100% most of the time since for both these brushes, I can control the opacity by pen pressure. Hope this helps!
Not too long actually. xD But then again, I wouldn't really know.. I never pay attention to the time when I'm drawing. I've been trying to figure out the average time I spend per piece but I ALWAYS forget to check the time.