I want to propose to rework arquebusier reducing the skill factor from some skills, increasing the number of hits that it does (the increase on number of hits could be reached by using the “clean hit” stacks) and increasing/reducing some cooldowns.
Pinpoint Fire: reduce skill factor.
Lucky Strike: reduce skill factor, increase the number of hits (i propose to make it deal 2 hits normally and 4 with “clean hits”), increase the “clean hit” stacks charged to 2 and make it be affected by AoE attack ratio.
Arquebus Barrage: reduce skill factor, increase number of hits (i propose to make it deal 3 hits normally and 5 or 6 with “clean hits”), increase cooldown to 20 seconds.
Dusty Salute: reduce skill factor, reduce cooldown to 20 seconds.
Precision Fire: reduce skill factor and make it be affected by AoE attack ratio.
The reason about this rework is that i think that currently is better to use other classes instead of arquebusier class. I think that currently its better to use falconeer/appraiser/hunter/sapper with cannoneer + matross/musketeer + tiguer hunter instead of arquebusier… An Arquebusier was supposed to be a good choice as 3rd class with both class combinations…
The “normal” effect from “Prediction” skill could be changed to increase the critical rate instead of accuary, it would make viable to add an effect to “Arquebusier Weapon” skill about increase the accuary by 20% when using musket and the block penetration by 20% when using cannon. The Art “Prediction: Perfect Hit” gives an unnecessary increase on final damage (the class has too much high skill factors)… As an idea, i think that it could reduce the effect by half (i’m talking about the new effect that i proposed (increase critical rate instead of accuary)) and make it increase accuary and block penetration by 15% too or reduce the effect by half and make it be “min. critical chance” instead.
Moreover, i want to propose to make the lvl 1 effect from arquebusier vaivora be an art (that reduce the skill factor of the skill too), and make the lvl 1 effect from arquebusier vaivora increase the number of hits from “precision fire” by 1.
Futhermore, i think that this class should have a vaivora cannon too (it could have the same effects), and an effect to cannoneer’s “Bazooka” state during “Desperate defense” skill as well (the added effect could be the same as “Sniper’s Serenity” but on “Bazooka” skill, which means that the current Art from “Bazooka” could be reworked as well). To finish, i think that “Desperate Defense” skill could have an effect about reduce the damage taken by 20% during its duration… This would mean that the effects from “Sniper’s Breathing” (from arquebusier about Leap skill) attribute about reduce the damage taken could be changed to make it charge 5 “clean hit” stacks instead (it would make viable a good combo to use “Precision Fire” skill after use "“Leap” or “Prediction” + “Lucky Strike” (with the increased number of stacks charged with “Lucky Strike” that i proposed) or after use it all while using the arquebusier vaivora).
I hope you like the idea!! 
Cheers