1. Yes, you can, but ONLY IF 1) your system is currently in UEFI boot mode, and 2) you are not currently using a RAID 10 (or have multiple arrays across the disks).
2. No. The PERC 6 does not support non-RAID/JBOD. RAID is ONLY risky if the USER chooses a risky RAID level (RAID 0 should only be used for specific reasons by experienced professionals).
RAID 0 has NO fault tolerance.