Bomb ... useless o_oOh god no; it's the best way to easily circle the map and collect UFO/point items everywhere! Since TH12 doesn't really reduce your score for bombing unlike many of the other games, you can pretty much bomb for points if you think that a lot of the point items are falling down too fast (e.g. if you kill too many things in Stage 5 and there's no UFO activated)
Plus, if a unit such as a boss eats every bullet that comes from Marisa-B's options (which is done by going really really near the unit), its power is actually a bit more powerful than Marisa-A. Of course this is difficult to pull off, but at least if you have invisibility time (shoot while bombing), you can somehow abuse this lol.
I agree that you might not get the most fabulous scores using Marisa-B, but at least you get to fuck Shou for free using it
