Can I use an ipad mini (wifi only) as a Gps if I pair it with my iPhone to use its Gps chip?

I don't think apple currently has a system to do that. What you can do is create a virtual hotspot with your phone and get you ipad mini to connect to that, but it would be Internet based but not GPS based.

Yes, you can: http://blog.urbanape.com/post/3798485232/show-me-the-way

Yes, sorry for my mistake, but I did a bit of research and it turns out that you can! If you have the iPhone 3GS or later.