Kaspersky stops after updating
(IMAP can and Google supports it, but Outlook does not) I think the problem lies with the Hotmail Activesync setup (Mobile Exchange).Your observation "With only the Apps account enabled, it seems to not lock up." would seem to support this conclusion - simply, whenever Hotmail looses the connection to Exchange, Outlook may freeze while it attempts to reconnect.
I would highly recommend to get a better idea of what exactly is causing Outlook to lock up.I hope this can save someone else numerous hours trying the same steps one by one.PS: this was outlook 2013, but it surely is valid for other outlook versions.I recommend using Hotmail in IMAP mode and see if your issues are still present. Outlook kept hanging up / freezing / not responding when I sent an email.I Even after a clean system refresh, online repair of office 2016, uninstall and reinstall of office 2016, only using an email account with only 100 megabits of data, deleting profile and resetting it 3 times, uncheck graphics hardware acceleration, and everything else I could find on the web, I finally fixed the problem on my Windows 10 machine.