I think options for diabling JS should be introduced, by default for background tabs user idle for more than 5 minutes. Pinned apps or an exception list should be allowed as exceptions. A right click option for each tab as an override. But if I havnt used a tab in 5 minues, more than likly (excpet rarely) I dont want it doing anything at all thank you! Exceptionsa re gmail (and other pinned apps)

A monitor on tab cpu usage would be nice.