VCF visualization is new to Galaxy, and mode switching isn't implemented yet. (It will be implemented in the next release.) What you're seeing is the display of individual variants; of course, trying to view so many variants leads to the mismash that you noted.
If you zoom in sufficiently, you should see variants without trouble. See the attached screenshot for example.
Everything looks OK so far. FYI, I've created a new page that lists the steps for setting up visualization for a Galaxy instance and updated wiki links/text to point to this page:
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