This will be really good because as of now you have to shutdown the server, disable command blocks, start the server, find the command block, break it or change it, shutdown the server, enable command blocks and start the server again.
Another nice feature would be a F3 + [something] to disable command blocks targeting yourself. This would only work if OPed.
Also would be nice to get command block locations somehow so you know where these commands are taking place. When working with a big team there can be bugs and like most programming IDEs, you are given the location of the bugs.(at least the ones the IDE's debugger can find)
I often work with teams to build and sometimes you get these people who for some reason TP @a 0 500 0 on a repeating command block.
So your idea of adding the command disable and/or a F3 + [insert key here] to disable such commands from targeting you would be priceless.