Just like laser designators for other guided munitions, the beam is invisible to the naked eye. You'd have to know you're being lased, know the color of the laser, and know where the shot was coming from.
The seeker on the bullet is going to have a limited field of vision.The bullet would not be able to see a target 180 from the point of aim. The amount of correction available is dependent on the speed of the projectile and the distance to the target. Gross corrections will drastically slow the bullet down, as it is not traveling under power. I suspect that there is a narrow field of vision, 24 - 30 degrees at most, that it has.
It will have nowhere the same kinetic energy that a conventional .50 caliber has using a 600 - 750 gr bullet at around 3,000 fps vs this much lighter, slower round.
Good anti-personnel round. Probably very useful against someone who is going to shoot at you with an RPG.