my mohawk is as wide as the top of my head and i LOVE it :) do whatever you like and however you want it to look lady! as for styling, if you do a basic fan or liberty spikes, thinner is easier to put up but if you do a deathhawk or want to do something more teased/fluffy, thicker works better....good luck!
i've had mine at different widths over the years, about 3 inches works best for me. i usually have it down and just clip the curls up with a big 40s bang in front. you can always grow it back in if you trim it to thin and wear it as a tri-hawk until it's longer :)