I actually forget to breathe sometimes. The body finds a way to force it, thank goodness; I'd be long gone if it didn't!
No missed opportunities here that I can think of, but as noted above I'm awfully forgetful =P A word of advice: get VueMinder and use it consistently. I'd be lost without it.
Have a look Vueminder - might be over the top for what you want but free version to try on Windows
You could then find the elements that you liked and start to think about coding them in the language of your choice & google for reminder examples in code
I like VueMinder. From what I have seen, this program should work good for you. I have only used it for printing calendars but so far this program is better than Outlook and Google Calendar for that. It also integrates with both pretty well.
Vueminder is the only software that I know of that can do most of what you are asking. It only runs on windows though, don't know if that will be a problem.
Unfortunately the free version only supports gmail sync; For the rest, you will need to buy it.
Listed feature:
Sync and Share Calendars Sync with your local network, Google Calendar, Microsoft Exchange, Outlook, iCalendar, and more.