You need to look at the pro's and cons of each raid scheme...
I wrote a pretty in depth guide a few years ago now. http://www.computerforums.org/forums...id-208367.html
Essentially. RAID 0 is just adding two disks together.
So if you loose one disk, you can't get data from either disk the drive/partition only exists when both disks are there.
That's why I said consider that for your I don't care disk to put backups of stuff just so you can have fast access and scratch or temporary data that you don't care about.
Raid 1 mirrors the disk, so regardless of the amount if disks in the array you only get the space of 1, the others are all backup copies in case a drive fails.
RAID 1+0 is a combination. You get big partitions and protection. If one disk goes your mirror is useless. But that's ok as the other disks have a copy.
RAID five needs to calculate a parity bit which means that writes take a while but reads from the disks are accessed Accross many spindles (lots of little chunks of data to make up the data) this means that read time is great (so it's useful for databases where you mostly want to read data, but terrible for places where you want to write data. On a system disk, or any disk with a page file you might see hundreds of writes per second, that's a lot of parity calculations that need to be done that will slow things down!
If you're using rdp, applications on the server and allowing multiple access to the data drive you may want to consider not making one big disk with multiple partitions.
When you think about it, the more people who are connections tge greater the demand for data. You only have one refs head per platter. So when three people want data at once they need to queue,
They'll also be fighting against disk read/writes on other partitions (which may require large head moves Accross swathes it disk space) and so keep people waiting or slow down the system.
Realistically, do you need blistering speed?! You might be fine with sharing spindles. You might find that your servers uptime and performance is critical, crediting a dedicated raid 1 set for system disks only...
It's a dangerous thing asking how should I do xyz, there's usually many ways to skin a cat! There may not be an actual right answer... And, it'll usually depend a lot on something that you didn't think of yet!!