2 ADFS Queries

Hi All, 

I have 2 questions that I am hoping you can help me with:-

1. Can I install the ADFS Proxy Server Role on a Server that is already a federation server?

2. When adding a manual relying party trust, this article mentions the importing of a certificate. http://technet.microsoft.com/en-us/library/dn486828.aspx. What certificate is it referring too?

kind regards

Hendy