I have trouble squeezing frosting through a small tip too, but it does not have to be very thick for the outline. I usually use a #2 or #3 to outline (more often a #2).
Yes, the black does bleed. Not so much with brown, but they can. I lay a papertowel gently over it about every 3-4 min until it stops condensating to absorb any extra (and prevent running). A clean papertowel each time. It usually only takes 10 min or so before it stops condensating so heavily.