[TS] Slicing the pie, a question?

[Ultraviolet]

In a situation where a tactical team is sweeping a building and a shooter is 'slicing the pie'

Am I correct in assuming this is excecuted as one step per round at a time? So one step, roll to spot (or it may be automatic succes) and the shooter may shoot if there is a target, but does not shoot if there is none. He announces in advance if he wants to evaluate before firing, for -2 to-hit.
If there is an enemy with a Wait he may also shoot, and this is the time to roll Quick contests to see who shoots first, right?
But if there is an enemy without a Wait, you just shot him?
If there is no target you take another step in the same round?

This sounds almost like a Move-and-Wait manoeuvre, but there is no such a thing?

The alternative would be to declare a Move-and Attack right? To rush in and shoot if anybody is there. An enemy with a Wait may very well shoot faster than you. So it is not recommended unless you're in a hurry!
But can you declare this and *not* shoot if there is no target? Is this similar to the -2 for evaluate? To say "I rush in and shoot at any target whatsoever, but if there is none then naturally I don't shoot"?