For (2) you can cut out the middle man (the mirror) and have the laser just point in the opposite direction of your desired acceleration. It amounts to the same

For (2) you can cut out the middle man (the mirror) and have the laser just point in the opposite direction of your desired acceleration. It amounts to the same thing, assuming the mirror reflects perfectly (by conservation of momentum - the momentum of the released photon is the same whether it bounces off a mirror first or just starts off in that direction).