Wow! Sounds pretty bad. It seems like you did a rather good job under the circumstances you were dealing with. These are the only things I can offer or have questions about.
First, I agree that NOW HP is a printing company, and I would always use Dell for my servers. I tend to lease them, and there are in the $4,000 range so not too sure how much your motherboard is. You are definitely having a hard time with your hard drives. What brand and type are you using. Also, didn't say how many drives in your RAID5. The more drives you have, the more dangerous it is.
I am not quite sure by the sentence, "I am hopeful that if something should fail with RAID 1, I would be able to pull a good drive and get my data off rapidly." Is that the same as just pulling the bad drive and adding a new drive and letting the mirror rebuild?
Windows 2008R2 is definitely stable, but if you install it, you are already four years behind the curve. I haven't heard anything about 2012 not being stable. Have you considered Hyper-V, etc.
What warranty do you have? Do you use something like 24/7/5 onsite?
Also, not sure what your IT consists of. Is the server being monitored daily. There are Microsoft specialists who completely run the server remotely and do everything and may have caught an impending drive failure.
Just thoughts. Not criticisms. Sounds like you are due for a good stretch.
Good luck.
Bert
