WordPress Template Amending and Fixing Permalinks

I have a wordpress website which was developed to a template that i chose. it is very good but when i moved hosting apparently some of the permalinks are broken so my colleague cannot get the site fully working. I would like this fixed.

I would also like to to customise the template to create 2 new sites. this means I would like to change certain aspects of the template for each of the new sites but not start again from scratch. It will also mean changing some of the Graphics.