Yes, we'd like to get the instructions for disabling MailChimp to SugarChimp communication as it currently seems to cause a crash in SugarChimp scheduled task, which in turn prevents SugarChimp from successfully pushing account list to MailChimp.
It seems that the sync never occurs after that failure. Scheduler is configured to run every 5 minutes and it did not run since last Friday (November 27th - when fatal error occurred per log snippet).
Also, trying to force the sync today (using two methods: 1. following instructions in documentation, and 2. changing field mapping and then requesting to re-queue for re-sync) has no effect - scheduler is properly dead like you described.
I will ask the infrastructure team on our side if opening SugarCRM to MailChimp is possible, but it might be difficult to get that through.