hi,
1- to mesure cpu usage for ios (use safari to preview because it gives you approximatly the same on device)
2- to mesure cpu usage for android better use chrome for preview
3-now you have to read 3 or 4 tutorial of ashley and other members on how to save your memory usage and optimize the game (cpu usage)
4-avoid every tick actions
5-beware of collisions check (desable them and enable them only when it is necessaire)
6-beware of behaviors (desable them and enable them only when it is necessaire) to
7-for me if i get cpu usage more than 40% its much .... your game will certainly run slow
8-try to enable Webgl if you want to use webgl
9-set pixel rounding to on and sampling to point in project propriety this will give you huge performance and remember to use render cell to on if you have large layout with collisions checks
10-we need to see your capx for more details and determine what is going wrong
good luck