A1. We recommend turning it off on all EMs else false positive conditions can occur or the three CEM services can still run on enabled EMs..
A2. If the MOM is not disabled, then the CEM MOM GUI should still be enabled.
A3.You are getting these error messages because the Collectors cannot insert data for the AppMap.
The best you can do is change the redirection for some of the events (add to IntroscopeEnterpriseManager.properties):