Just like anything.......once you have done it once ... it's not a scary thing anymore
To answer most of the other questions .....Think of it this way...............when you have a single drive, you back up your Data and settings...this is good, because this is the most critical thing you cannot replace ... but if that
single hard drive fails......All 0 and 1s are toast....as in all the OS , Programs and data are gone.......Once you replace the drive with a newie..... you will still have to reinstall the OS, all your Programs from disc or download and re-activate them ....( you do have a copy of all your activation codes don't you).
.... then finally copy back your carefully saved data and settings ... so how long has that been .... 3 days? ...maybe 4 ?
When you have Raid , you
clone your drive/s .... even 6 drives in Raid 5 looks and feel like a single logical drive ... so it can be copied ( cloned ) to another single drive that you can connect externally to your computer ... this is your master copy ... if you have a catastrophic failure of say your whole system ,eg Lightening strike ... you can rebuild your system back to it's original condition and load back your clone ... not only will this load back the OS but everything........even your programs will be reinstalled including the activations applicable .... in fact it will be exactly the same the minute prior to when the clone was struck .... even you desktop will look exactly the same
Funny thing is also ...Raid 5 works best with odd numbers .... When I was using Raid for near on 5 years ... I found 5 drives to be the sweet spot....this way you can have a hot spare in the system ready for a drive failure if lady luck strikes...this way you still have your redundancy while you rip out the bad drive ... RMA ... and get your replacement .... when it arrives ... you pop it back in as a hot spare ... many Photo houses use this practice because it works.
I have a setup where I won't go into details but .... if I have a catastrophic failure say at 10:00AM and there nothing to replace .... I can be back working in under 1 hr and the most I can loose is about 6 hrs of work ..... My clone continuously updates 4 times a day.
Hope this answers your questions
Aussie Allan