So, it would appear that you cannot remotely drive any rampant vehicles. I honestly am very confused as to how this hasn't already been reported. I doublechecked multiple times, and I can drive the normal tank and cannot drive the nuclear tank. Nor any nuclear trains, for that matter.

A quick glance through the files and comparing to the vanilla tank indicates that the vehicles are likely in need of updating. No sign of 'allow_remote_driving = true' can be found.

Yep, adding 'allow_remote_driving = true' to the tank in 'VehicleUtils.lua' allows you to drive the tanks remotes as intended.

Yes. Actually, there are two parameters needed:
is_military_target = true,
allow_remote_driving = true
otherwise the biters won't perceive it as a threat

Ah, that was the missing part that prevented them targeting it! Makes sense.