@first question: i'm not much of a fan for the melee necro set , but if i were you i'd max the ED and get leech , as you allready figgured that out
@second question: SU's are not a must to get all the charms , but some strong crafts/ end game runewords are required to reach certain values of damage/defence/resistances/other stats depending on the build you pick .
the javazon is probably the less gear-dependent build that can do that [dexterity crafts/one or 2 runewords/socket perfect gems /respec to smax the proper skill you need (more damage/more defence) -> win]