Installation Question -- Will I be doom?

[thephatp]

Sorry, didn't really know what to title this, but didn't want to scare anyone off with RAID in the title.

 

My main concern in trying to install OS X on my PC is messing up my current machine. I have two internal hard drives (750GB), and I currently run them in a RAID 0 configuration. The first partition of the RAID is for my OS and is not redundant (so that I can reimage whenever I want and not worry about losing files). The second partition is the redundant section, which contains all of my media files, development files, etc. that I want backed up. I don't want to have to change any of this, so I was considering installing on a separate external hard drive.

 

Here are my two questions (so far ):

1. Is there ANYTHING at all in the setup guides that are required which could hurt my current setup?
   1. 
      
   2. 
       
      What is Kexts?
      
   3. What about my disks being in RAID?
      

[*]

 

What is AHCI for and why is it needed? I don't want to change from my RAID setup, so I hope I can get around this somehow.

I have a GA-P35-DS3R v2.0, E6750 Core 2 Duo, X1950 Pro vid card, Audigy Platinum with front panel, 2x 750GB SATA Seagate drives, Sata lite-scribe DVD RW.

 

Any info is greatly appreciated. I'm so worried I will do something, set a setting, or install something that will mess up my current rig.