Question: Switching spotters for artillery bombardment

[rri970]

I'm trying to get my grips on some finer points of artillery usage that I was not able to figure out from the manual.

1) Can different spotters be used to assign different bombardment missions within the same turn?
Example: I assign two of my tubes from a battery (say W0 and W1) using B0 as the spotting unit. I close the bombardment screen, select C0 as a spotting unit, open the bombardment screen and assign firing missions for guns W2 and W3 from my battery.
Is B0 still the spotter for W0 and W1, or did they switch to C0 as the spotter?

2) Does using a new spotting unit to adjust an assigned bombardment mission change the spotter for that mission?
Example: I've used B0 to assign all tubes of my W battery to a fire mission on the previous turn. This turn, I open the bombardment screen with C0 as the spotter, and use the "arrows" icon to adjust the bombardment mission. Is now C0 the new spotter for my W guns?

3) Is there a way to switch spotters for an assigned mission without "adjusting" it?
Example: My spotter B0 has been forced to run for cover by the dastardly enemy, but brave and cunning C0 still has LOS of target for a pending bombardment. Can I switch the spotter to be C0, w/o "adjusting" fire? I assume "No", but thought I'd ask.

Thanks in advance!