I do not understand why you guys are so against Mogg Fanatic. This card is amazing as it pushes through a lot of damage over the coarse of a game. Its a must answer for a lot of decks that many players seem to under estimate.
I would not run less than 4 in a goblin deck that I would play. If you want to look for room in order to play Earwing Squad or a different goblin, I would look at other choices. Goblin piledriver comes to mind as its the first goblin I would think about cutting, since its only good with multiple goblins already in play.
If you go with just the R/B configuration, I would not play Frogtosser Banneret b/c he seems just too weak in a deck where quality matters, more so than speed.
If people don't play either plague or enchantments that you can't deal with, then by all means go with R/B, but in some metagames you can't get away with that.