Federation Commander

According to rule 4J3d, if a plasma torpedo launcher with a fully-armed torpedo is disabled, the torpedo can still be launched anytime before the end of the turn.

Furthermore, the torpedo may not be fired as a bolt.

Can the torpedo be upgraded within the disabled launcher? For example, if I'm holding a G-type torpedo in a disabled S launcher, may I upgrade it to an S before launching?

Without checking the rulebook, I don't think you can. I know you can NOT do that in SFB, so it would be very surprising (to me) if it's allowed in FedCmdr.

No, you can't. Once the tube is disabled, what you have is what you get.

It's not actually the Tube/Launcher that is damaged.
It is the Arming Device.
Which would prohibit using Holding Power,
or Upgrading.