I've completed a first attempt at your suggested 'silent' mode.
It now runs is 3 possible modes, NORMAL, NOTIFY and SILENT
NORMAL = Full interactive menu and prompts - You don't need to set this anywhere to run script as normal
These 2 are intended for launching script from Autoexec.py (included and currently set to NOTIFY)
NOTIFY - Checks for new build and notify, nothing downloaded or processed.
SILENT - Checks for new build, if found does full installation (with notifications) - Prompts for reboot on success.
I think I've balanced the amount of notifications in SILENT mode.
Copy included autoexec.py to Q:\scripts if you wish to use it.
Only problem I can see is that xbmc.Notification() seems to ignore the time arg passed, this has been mentioned before in another thread when I researched it. Couldnt see a fix reported.
b18
HERE