Hi,
Thanks for using our plugins. We do not have any registration features, you can use one of our ticketing plugins for registration, but it is not a direct system to do that.
What are you using for registration?
Please note any of our ticketing solutions do not support recurring events so you are running into an issue were the Recurring Series is considered one event so yes any updates to one will update them all. You would have to break an event out of the series to give it different information from the rest.
Let me know what you are using for registration and I maybe to help out.
Thanks