Optimization Using Event Groups?

Since it seems C2 checks all events on the event sheet every tick, would it reduce CPU and memory usage if I grouped various events under groups and only activated those groups in situations where they would apply? And would the gain be significant enough to be worth the time? I currently have 341 events at 67.3 mb memory use.

One word: yes

Not only it deactivated groups are not processed, but also they help organise your project, and they also make the debugger profiler tab really useful.

If the amount of work is really too much for this project in the ned, still keep it in mind for the next project you may do.

PS: since it involves quite a lot of modifications, remember to do a manual back up before hand, so you can make mistakes without losing too much.