It's 1 AM and I should be asleep but I'll answer some of those points with my addled brains.
I think Slow and Steady is to strong, there are so many skill you could learn to relocate yourself without having to move by foot, I think the negativ aspect would hardly make any difference for the warrior. Warriors alone have 3 such skills at least for such purpose. Also don't think there is a need to disable the pawn for it. Slow and Steady totally reduces the worth of The Pawn, because movement range of the Pawn get diminished as well.
I can't think of the third warrior movement skill. I'll think about this one some more. Maybe reducing the movement further would help, relocation skills do have cooldowns so they can't be used constantly. Plus the more Memory slots you spend on relocation skills, the fewer you have on the more powerful skills. That in itself reduces offensive power a bit, doesn't it?
Zeroed In sounds interesting, but a multiplicative Bonus would be 40 + (20% of 140 = 28), so a total of 68

Err... right. That's still more than 60, though. So it's the smaller bonus which is what I meant to say.
So using flesh sacrifice would cancel it aswell? Perhaps your AP are full, so you need to make space first. Also tactical retreat would be kind of a movement. I think any kind of movement should cancel the bonus, because you changed your line of firing. Boost who don't effect your position should not cancel it.
Using Flesh Sacrifice before making your two+ consecutive shots would not cancel the bonus, and you would retain the effects of Flesh Sacrifice. Using it after making the two+ consecutive shots (and triggering the bonus) would because it is a skill.
Using Tactical Retreat would cancel the bonus because that's a skill. Using any skill with the bonus up cancels it. I do think using your AP to move should not cancel the bonus.
My reasoning for allowing direct movement is that enemies can move around and get themselves out of range. This bonus is about Zeroing In on one specific enemy and targeting them relentlessly with regular attacks. I think chasing them down to continue firing counts.