There, title pretty much sums it up. I think I understand how to spend SP in DPS role - two full weapons for melee or ranged combos if weapon expert, one full weapon if hybrid, no points in weapon if superpowered - but I'm not sure about tank, healer, and controller roles. Obviously going all the way down my weapon tree to weapon mastery is unnecessary since I don't need to deal damage. But, should I not spend any points at all? For example: as a dual pistol controller I like my Slip Shot and Jump Shot, and I don't think Sweep Shot is all that useful. But I'm very uncertain about Loft Shot and Magnum Round. On my staff tank I only spent the necessary points to reach Leaping Overhead Strike. All in all, is there some kind of "magic number" (meaning no more, no less) of skill points I should put in my weapon while supporting?
It depends on which weapon you're using for support. Some combos are more efficient for power back than others.
I just use enough to unlock Solar Flare for Handblasters as it’s my weapon combo of choice for power back.
