Enterprise Core-based Licensing for SQL2012

We have a 16 core SQL Server 2012 Enterprise License for a server.

Question 1: When installed, does this mean that SQL will only use 16 physical server cores even if the server has 24 cores in total?

Question 2: Not taking account the disk or RAID layout of the server, would you chose to have more cores OR a faster processor. Assume this is a mixed use server, some data warehouse, some OLTP.

Thank you,

Denka