The solider I talked to could just be lying or maybe not even know himself.
This was post cold war when the agreements to stand down ICBMs were rolling out and they were disarming and imploding silos (Russians came to observe even). So I think it was plausible that they were moving things. But yeah I have no way to know, a drill, real deal, it would look the same to me.
Maybe. Sowing confusion about the whereabouts of your warheads can be useful, and that was extensively considered.
See for example https://www.princeton.edu/~ota/disk3/1981/8116/811604.pdf, discussing the never implemented “multiple protective shelters” concept.
That even discusses how that can be done when treaties require inspections to be able to count your missiles.