Hmmm. I just restored the above config and almost nothing is working. Perhaps there’s a lesson there for me to reboot the device more often. I’ll start over and report back. Thanks for your advice. The PVID in the wifi bridge ports is mandatory btw. I hope that doesn´t cause any problems.
Edit: I accurately redid all the steps in RouterSwitchAP.rsc from http://forum.mikrotik.com/t/using-routeros-to-vlan-your-network/126489/1 by hand and I was up and running within half an hour. Next step is adding the cAP.