1. Add a (new version!) Calendar portlet to your page.
2. Be sure, you have one My Calendar and one Current Site Calendar at least. If you don't, Add a Site Calendar.
3. Create a repeating event into the Site Calendar.
4. After you saved it and closed the dialog box, click on any of element of this event series.
You see the Calendar dropdown box shows your own calendar instead of the site calendar.
5. Change it back to the Site calendar and change the Title.
6. Click on Save, then All Events in the Series button.
The change of title only affects one element of the series, not all events, as you wanted.
The second part of this ticket is similar to
LPS-31922 but not identical.