Don't think that Sea Sprite is only in the deck because of Goblins. Red is the second most common remoaval color being run in Legacy. Sea Sprite will greatly help out the Goblin matchup, as well as the UGr Thresh, Red Death, R/G Beatz, BDW, Sligh, etc. matchups. Weatherseed Faeries are a good replacement, but slightly harder to cast.
Rainbow Efreet is a beast in the control matchup, but I can't even imagine how long I'd have to wait to get the 3UUU I'd need to cast it.

