So what's the ideal mesmer weapon?
I'm currently using Staff and Scepter + Pistol
I love my sword/sword. It's great for a shatter build, the sword phantasm from the offhand weapon has a really low cooldown, deals it's damage in single strike so you can shatter it quickly after, and on top of that gives YOU a leap finisher. Also the sword block makes you more tankier as well. Pistol is not a bad offhand either, if you're not shattering immediately and rather keeping phantasms up.
I usually start with the summoning the sword phant, then jump in with the sword "3" skill, dodge or block once to create one clone and explode the mob to pieces. Takes a few seconds and you're not really spending a lot of time in melee
If you're fighting multiple enemies you can always do Blurred Frenzy (which makes you invulnerable) before shattering to soften up the secondary targets.
That said, I usually have a staff in my weapon swap, just so you can support and deal damage from range if you need a bit of a breather. It's also pretty fun to drop a Chaos Storm somewhere and leap through it for a bit of Chaos Armor.