Does the Headway theme mess up 'Wiki'?

I've installed 'wiki' on top of the Headway theme, and there are several things not working. I've messed with the settings in the visual editor as far as I know how & fixed some elements, but not all.

These are the things I still can't fix:

Clicking on a tag in tag cloud gives a whoops page.

comment submit takes you to a ‘whoops’ page.

breadcrumbs top level – no page - I posted that already.

Supposed to be able to control settings from the front end – comments ok, who can access, parent, categories – Headway must be interfering somehow.