I don't have a XP-m cpu, yet. I'm waiting for bios modding for 133 Mhz fsb.
For 2nd and 3tr point: clock generator support frequencies till and over 150 Mhz, i have been tried with softfsb a time ago, but cause memory speed (100 Mhz cl2) and agp/pci divider it can't go over 115 mhz (agp will go over 80 Mhz) and pc hangup!!
Bios sets clock generator but it's blocked (by Sony) to 100 Mhz.
Thank you for your help
PS: Sorry for my english, i don't speek and write it very often