

Something to note, some AF ACT operations can be contracted out. This means that even the AF doesn’t have enough even for its own operations, and that number probably reflects the available number of ‘wartime’ operators available.
Also, the military operates under a huge umbrella of tasks, where a 1C1 wouldn’t ‘just be’ ACT - that would be your ‘wartime’ job (specifically when you first enter), and you are ever becoming more generalized to handle a broader scope of tasks and responsibilities. If every 1C1 were used, you’d lose a lot of managers, support, training and etc to put people who are 1C1 who may not have done ATC work in years. Think First Sergeants and the like, they could do it - but you’d lose someone who has the knowledge of all 1C operations and go back to just doing ATC. That’s a heavy ask.
So the outlook is even worse than you suggest.

This is a case of 'it depends '. The damage isn’t caused by something being on or off. It’s everywhere. Disconnecting can isolate damage from small storms, but world ending storms have enough energy to jump air gaps and the surges would be faster than most breakers can react to. You’d physically have to rip the cables from your house to be safe. Smaller, battery powered devices would be more susceptible regardless if they were on/off. Batteries are a concern because you don’t want them to incur damage/blow up due to an electric surge.
If this sounds overblown remember that during the Carrington Event, telegraph lines continued to operate for hours even after batteries were removed. In some cases, lines sparked and damaged equipment or personnel. These are very powerful storms that naturally induce electric current in circuitry.