I have actually thought of an idea to help with the lack of AP DPS. Basically, put in a skill that, while using High Energy Gas Cylinder, removes the channel on Flame Thrower. So basically, you hit the button, the ability goes for 3 seconds, but you can still move and activate other abilities. Maybe give some abilites a chance to reset Flame Thrower's CD as well.
And increase the damage of Retractable Blade and Immolate.