Yes, and yes.
If properly wired (and this is always a potential issue), neutral wires are white. Hot wires are black, red, sometimes blue or other colors except white and green (which is reserved for ground).
Basic switches that have no electronic components simply make or break the hot wire. One side is hot and the other side is switched hot. Modern switches also have a ground, which is green or bare.
More complex switches, such as electronic dimmers, some lighted switches, wifi switches and others also need a neutral.
In the switch you have shown, the two hot contacts are attached to the black wires shown. If your switch has its own wires, the white wire is attached to the existing pair of white wires, and the proper sized wire nut then put back on. A white pigtail (a short length of the same gauge wire) should be connected to the neutral terminal of the switch if it doesn't have its own wire.
The two existing black wires should be attached to the hot terminals on your new switch. Also attach the ground wire to your switch, either directly to the ground terminal or to the ground wire.
If your switch needs a specific connection to the hot wire (also called line), you will have to test to see which of the black wires is hot and which is switched. If so, ask and we will explain how to test.
When you addressing two 3-ways and one 4-way. Remember that one side of the common on the three way is the line side and the other common is the load side or switch leg. The two wires that connect between the 3-ways switches are carriers. If you have a 4-way it simply flips the carriers, two carriers in two carriers out. So, no there should never be a configuration where a line side "hot" leg will be connected to the 4-way. Although it may pass through the box.
Other than that the only other way to save time is to have a helper turn the breakers on and off to save you some steps, or employ a circuit tracer to trace out the circuits. These may be well and fine for someone who is doing a large number of circuits but usually isn't cost effective for a one off DIYer.
Good luck
Best Answer
You may or may not have any neutral wire in the box, depending how it's wired.
With switch loops (which you can't do legally now, but could for a long time) there's quite often no neutral. Assume any white wire connected to a dumb switch is hot from a switch loop.
Otherwise, with dumb switches, look for a bunch of white wires not connected to the switches, but connected to each other.