Here are my answers:
Second: You should create your RAID0 by using the RAID utility, then install the OS by loading/integrating the needed Intel RAID driver (IMSM or ISRT).
Third: As long as you have just 1 SSD, you should run it in AHCI Mode. If you would buy a 2nd SSD later, you will be able to create a RAID0, but I recommend to take the new Intel(R) Rapid Storage Technology (IRST) drivers and not the IMSM ones (much better performance).
ok, so setup with AHCI mode, get the Intel(R) Rapid Storage Technology later on when a 2nd drive comes along and all will be good.
Thanks for helping me out!