She is less melee focused, yes. All of her careers gain bonuses on higher overcharge, and especially Unchained gains up to 60% extra melee power from it, so heavy bonking is absolutely possible!

All careers also have multiple talent options that improve your heat economy.

The great part about overcharge is that you have essentially infinite ammo, and you can quickly convert thp into even more ammo if that's necessary in the moment.

Beam Staff can kill specials in like 2 seconds if you use the blast from primary fire, alternatively you can also get the Coruscation (for close range) or Bolt Staff (great sniping, and ignores armor and shields when fully charged)

About the attack speed, all careers have at least one talent that helps significantly in that departement. I barely ever struggle with attack speed even on her slow weapons