pikes come in all sizes. range probably from like 4"-20"
id say most commonly pikes are in the 12" range at max size. then there are the dwarf species and the venezuelans which can get to 20" but most are around 12" id say.
ive never kept venezuelan but i believe they have pretty much the same temperament as all other pikes. typically with all the pikes ive had, ive noticed aggression towards other pikes and sometimes other big cichlids. the pikes ive had have always liked to stake out one cave or something to call as there spot. they typically show some aggression if they feel someone is intruding in there space. generally its not like "i wanna kill u" aggression, more like "this is my space get the **** out"
ive never known a pike to just want to kill everything but im sure a few people have pikes like that. over all id say it could probably work out fine.