Multi-purpose trait line?
Tools and Alchemy are your friends. The Alchemy traitline is probably one of our best traitlines. It provides tons of defensive abilities that are extremely strong in all builds, from glass cannon to tanky condition damage to bunker build.
Tools is quite strong for all builds due to the traits it provides. 10 deep can grant you permanent swiftness while using a kit, 15 deep provides a last-chance toolbelt reset and 20 deep allows you to trait Tool Kit for cooldown reduction, which is a kit that’s great for almost any spec.
I’d probably go 20-30 in alchemy, 10-20 in tools, and spread the rest out between the final traitlines depending on what specs you typically play. Hair trigger in the precision traitline is great if you run rifle. I’d personally only go into toughness if you’re playing PvP, since those traits are designed for fighting players.
On an off note, you mentioned stacking might to increase damage. That usually doesn’t work very well unless you’re using a mixed damage kit such as bombs or grenades, where most of your attacks benefit from both the condition damage and the direct damage increase from might. In comparison, Juggernaut (which requires staying in flamethrower to proc) is typically for the added tankiness, not the damage, since Flamethrower doesn’t scale very well with might. If you were looking for the best damage for your trait spec, that was the wrong way to go, but the Flamethrower does have a few perks over grenades.