Generally either you're going to pick one of melee, ranged, minions, or fifth-wheel support and be good at that one thing, or you're going to pick two of them and be slightly less good at both; and you can respec on a day-to-day basis as the situation demands.
Meh, Lightning Gauntlets and Dissolving Spittle use two of the least resisted energy types, so it's not nearly as glaring a weakness as, say, sneak attack being useless every third encounter. And you can also have minions with your necrocarnum zombie and/or soulspark familiar, neither of which cares about your BAB at all. Or, if you're going the UMD route, you might have wands to fall back on when your primary attack is ineffective. Or heck, maybe you're using weapons after all and you still don't care about BAB because you can just use one or more of your soulmelds to boost your attack and make up for it—with Incarnate Weapon, for example, you only have +1 BAB at 3rd level, but you're swinging a +3 weapon where the martial character is lucky to have a masterwork one, and you still have two other soulmelds and a crown bind. I call that a net win.