This is a feature request: Instead of importing certificates in the android keystore - which requires changes e.g. a pin code - implement an application keystore and a dialog to import server certificates and remove certificates.
This patch adds support for tor hidden-services, which allows you to host e.g. owncloud without the need for a dyndns service.
Davdroid will use a socks proxy (on 127.0.0.1:9050) to connect to a .onion address.