Hi Stephan,
Sorry to hear my fix didn't work for you. That method was specifically geared to iCloud calendars.
I would definitely suggest you changing your default calendar on your iCal to a calendar currently on your iCloud (e.g. I have 4 iCloud calendars: Personal, Business, School, and Work):
> Open iCal > Calendars > Preferences > General > Default Calendar
You can pick one of the iCloud calendars that you have, and the events you input on your Mac should now show in your iCloud, as well as your iPhone.
Back to your question. I'm not sure I understood it correctly. When you say "local calendars," do you mean another email account (e.g. google, yahoo)? You can make those calendars visible on your iCal and iPhone (as opposed to transferring all events over to iCloud).
*On the iPhone*
If an email account, you can go to your iPhone and set up that account:
> Settings > Mail, Contacts, Calendars > Add Account
OR simply enable the calendar feature for those accounts.
> Settings > Mail, Contacts, Calendars > Click on account > Make sure "Calendars" is green/on
Once that's in, you should be able to see changes reflected on your account and your iPhone.
*On iCal*
Enable the account calendar (check the box) if you see the account on the lefthand side.
If not, add the account on your iCal.
> Calendar > Add Account... > Select account
Hope this helps!