To answer your questions… the Feedback damage increase is an upgrade as described here - it’s still 0.5 HP per 1 energy initially, so early drops aren’t affected: [Suggestion] Feedback Upgrade
To recall the interceptors back to the Carrier, you have to pull the Carrier out of range of the current target - a new hotkey so they can do this without moving out of range (and moving the Carrier so they don’t instantly redeploy) is a nice thought though, and might make for some interesting play against Widow Mines.
The +25 Energy Upgrade allows warped-in Sentries to cast Guardian Shield right off the bat, so it is more defensive than anything else, but it might open up some sneaky Hallucination play - more details here: [Suggestion] Sentry Energy Upgrade
And the Mothership energy regeneration allows for more use of Time Warp and Recall, as well as allowing the unit to recover more quickly from EMP and Feedback.