Asking for advice
Ugh blank armor O_O I dunno how to comment.
1. What is ur role
If u want to use power, prec, crit I assume u want to become Hitter role. Well GS fits that role. For 2nd weapon set Staff is good but lack of burst to focus fire enemy with ur Allies. MH Sword also good to dive into enemy zerg/ team, land AOE 2sec Immo + Blurry Frenzy then run away if their eyes on u.
2. I like Debilitating Dissipation in CHaos Trait
Debilitating Dissipation vs Illusionary Defense. I used to like Illu def. Makes ur Char really tanky coz it reduce enemy damage by %. But 2things changed my mind. First, A Good thief will CnD on ur clone then get close to u while in Stealth. If u have Debilitating Dissipation when the thief CnD on ur clone it will give either Weakness, Bleed or Vul to that Thief + The Condis is AOE. If u are lucky it will give the Thief weakness, it will lower his damage. 2nd Coz the condi effect from Clone when death is AOE. It will help ur teammates also. Let’s say ur clones died in center of enemies and all of them got Weakness for next 4s. It’s kinda gambling but worth IMO.
Btw most standard Mesmer Playstyle in zerging is Drop Veil/ Null Field then peels off to become backline damage so GS is a good choice for teamplay/ Zerging.