I want to put put Kontact in an encrypted folder or disk, to make sure nobody can access my mail/contacts/calendar even if they gain physical access to my computer.
With Evolution it was pretty simple. I just copied the Evolution folder and symlinked it from an encrypted disk.
Would a similar solution be practical with Kontact apps? And what would I need to symlink? One problem I am afraid of is KDE would not start at all or might get corrupted if I didn't decrypt the disk before starting kde. Thx in advance for any advice or opinion.

With nobody interested I will have to try to respond to myself. For what I've managed to read in the meantime, selectively encrypting Kontact data does not seem practical.
It might be possible to use encrypted activities as described here http://ivan.fomentgroup.org/blog/2012/0 ... ctivities/ and here http://ivan.fomentgroup.org/blog/2012/0 ... in-kde-sc/ , but this way you can only create a semi-secure set-up, lose some functionality (full-text search) and would have to get used to the alien idea of activities.
I'd rather lean to full disk encryption - much simpler to achieve and offers real security.

Encrypting activities has been removed in recent KActivities versions as it was half-done and not really secure. The best IMO is to use full-disk encryption for this.