Full Volcanic might be the safest option for you if you're primarily a support bomber, as Mad's offensive bonuses won't be as useful to you. A Damage trinkie should be enough of a damage buff.

Both of those set ups are viable but I would highly suggest you get an Electron Vortex, it will help your party out immensely by gathering all the monsters into a compact group, allowing them to unleash charge attacks into the crowd and you'll tear through levels considerably faster. It can also be used as a DPS bomb to a certain extent if u learn to chain them.

As Bopp suggested, you should probably leave Shiver off your default loadout and mostly keep it for FSC (mainly Vanaduke) and Shadow Lairs.

For a general set I would recommend something like this:

EV
AoA / VT
DBB / V V / Nitro

Use VT over AoA on fire themed levels. DBB on anything that doesnt resist it as the lack of knockback wont hurt your teammates as much and Nitro in other cases. There's always exceptions of course, sometimes knockback will be extremely useful, use your own discretion. V V may prove more useful when there's many healers. Against beasts and gremlins and maybe fiends where EV wont be as useful, bring a DPS bomb or an extra status.

AoA also pairs nicely with VT, particularly in arenas or the RJP.

Kxdx, vortex bombs can be delightful. I mean, if you're playing with guildies who go nuts with sword charges when you start dropping vortices, then they're great fun, and they can really speed up fights against crowds. If you're playing with randoms who ignore your vortices, then they're depressing. Anyway, you should definitely try them. (Notice that EV requires lots of PvP. GV doesn't, but is regarded as slightly weaker.) But I think that both VT and AoA are more widely useful, and hence a higher priority.

If you solo a lot, consider sometimes carrying an elemental gun (or maybe Valiance), as you're going to have trouble against fields of turrets. Also, sometimes you will use your third weapon slot just for heating.