I very seldom run out of mana on my rogue but I have a weird (probably not the best) build with smoke bombs maxed out, poison arrows at 3 and then the blade skill that if you charge it your rogue zips around the screen like a rooster in a chicken farm. Works well for me. I got a few deaths but been playing with a level 9 to 11 through the levels near kraag town so to be expected (also I don't care about k/d ratios so am tend to be careless )