[Solved] RAID 1 - Two Part Question

I am going to set up a home server. I have not decided on an OS but will use either Windows Home Server or Windows 7. I am going to upgrade all the computers on my home network and add an HTPC. I will most likely upgrade the other systems to Windows 7 (I have access at low cost to Win 7 Ultimate).

Question 1: Does RAID 1 slow performance of applications? I've read a bit on this forum and it sounds like some hit is taken to performance but that it is minimal. Is the performance difference a real consideration? I already have the second drive so there isn't any hardware cost.

Question 2: Can I have two separate RAID 1 arrays on one system? My thought is to set the server up with a disk dedicated to applications and a RAID 1 array set up for network storage and media sharing. Could I set the application disk up in a separate RAID 1 array so that the applications are mirrored? Array A would be an applications array, Array S would be a stoage array.

Thanks for your definitive answers. I've been able to find comments and articles that seem to answer these questions but I'm not confident that my conclusions are correct.