Actually I wouldn't worry at all about most Every Tick events. The biggest source of slowdown on mobile is related to graphics, not logic. Unless you've got some hardcore physics calculations happening (EDIT: or insanity with loops, and other serious logic slowdown issues, anything way out of the ordinary), forget optimization and just make sure your code is organized and pleasing to the eye. Setting A equal to B every tick has practically zero impact on performance. Ashley has addressed this on his blog. If you haven't already, read it and feel relieved. https://www.scirra.com/blog/83/optimisa ... -your-time
The best advice is to periodically export the game and check its performance on mobile. That way, if you made a change that breaks performance, you can re-evaluate your approach.
Also, CocoonJS Canvas+ is the best export option when it comes to performance, there's no doubt about it. Because it's a "non-browser engine", Ashley doesn't like to promote it, otherwise users complain about Construct 2 being flawed when there are compatibility issues. The truth is that CocoonJS Canvas+ is WAY better performance-wise than Crosswalk, especially when it comes to twitch-based action games with lots of movement in them. So forget compatibility. If you are developing strictly for mobile, and CocoonJS Canvas+ works for you, then develop to export through it, and you'll get much higher quality results than Crosswalk.