Sorry, I don't really know... Action Camera itself does what autohotkey was doing before by positioning the crosshair. I don't use autohotkey at all anymore (just Xpadder) nor do I ever switch off action camera during combat.
I mean you obviously don't have to use action camera at all, if it isn't beneficial for you. In theory just fudging mouselook by using a script to permanently hold doing the RMB still works. But if you can't get autohokey to do what you want with the mouse then I'm not sure. If it's just that it positions the cursor somewhere other than you want, but is still able to reset the cursor in the first place, I'm sure it can be modified.
edit: In rereading my old posts about this, I realize I was never able to get AutoHotKey working properly with Windows 8, let alone 10, and Action Cam was what basically saved me in order to still be able to play GW2 with a pad at all after upgrading. So I have no idea about the best solution to the way you use cursor aiming.
In the new iteration here Cursor Mode is also back to being a "hold"- I'm not sure if this makes it more or less annoying to use for you. In playing around with it I know what you mean about the cursor not resetting if you're going to aim like that frequently. You can manually "drop off" the cursor back in the position you want it after you cast the skill, which is not an ideal solution at all but might help you.