Hadron, many thanks for posting. It seems to me that the stock calendar app is broken, since the settings I've specified suggest that I should be getting an alert when an event is scheduled. But if I can fix it, and my other problems, by installing apps then I suppose I'll do that. I'm just not used to having to install things to get my phone working the way I want it to.
Thanks again, I appreciate you taking the time to help.