Eii, thank you! That worked great.
EdH, auto-sync still works.
The main problem here is not the "icon", but the extra "app" to which the icon belongs. Sorry if I was not clear on this. Systray icons typically belong to a separate app/process from the app's main process. Therefore, merely hiding the icon does not achieve the goal.
In order to allow revert back to original operation in case of causing app errors... Instead of deleting "EvernoteTray.exe", I renamed it to "EvernoteTray_DISABLED.exe", then created the text file and renamed it as Eii had suggested.
Seems to be working perfectly so far.
The fact that the tray app/icon cannot be disabled seems to cause it to behave as pure "bloatware" in my case - which I hate. I cannot think of a single use case for myself where Evernote is not "visible" - at least not for more than 30 seconds if I happen to go to a different app's window.