You can safely run the repair, your current configuration and settings will be left untouched.

You do need an active OL Care subscription to get Tech Support.

That said, you haven't posted the results of trying out the suggestions made by Raphael. In particular, the one about launching the Designer while holding down the left CTRL key, which will reset the visual preferences in the Designer (it won't mess up the templates or anything else).
Technical Product Manager
I don't want to achieve immortality through my work; I want to achieve immortality through not dying - Woody Allen