FOTRS Ultimate Beta is 2.8 GB uncompressed.
It includes 738 folders and 6291 files.
As RR said, JSGME needs to be used very carefully before enabling this monster of a mod.
A way to avoid uninstalls and reinstalls is to have a complete unmodded copy of SH4 in another location on the disk. Read only status is highly recommended. When you need to install or reinstall a FOTRS version, delete the whole SH4 folder, copy the backup one, and install FOTRS using JSGME.
This way, there's no chance of JSGME "forgetting" something and it's A LOT more quick procedure than reinstalling the whole game. If you can spare 5 GB of disk space, I recommend it.
It seems I'm the only one having weapons & sensors working during patrol. Not that it matters so much anyway.
Cheers, Billy.