For "personal needs", RAID really has no value. Gaming performance increases by 2-7% tops for example. Biggets impact it has is in boot time and a SSD will do a better job at that. In RAID 0, the chance of a HD failure remains the same as a single drive but since one HD failure takes out all data on both, your risk is doubled.
For data security, RAID 1 saves everything in case of a drive failure. But of course, in case of theft or fire, that doesn't mean beans. My suggestion for a home setup is a single HD or SSD / HD on each PC with a NAS in RAID for everyone in the house to use. In case of fire, grab the NAS and run
It depends entirely on what kind of stuff you are keeping on the hard drives. If a hard drive failure would lose you nothing but time, and you don't mind losing the time, then you can just do a raid 0.
If you are keeping files that you invest time in or cannot be replaced (ie. personal pictures, game saves, financial data etc.) you should either use some form of raid with redundancy or manually back them up.
As far as failures, technically a raid 0 setup is more likely to fail simply because you are using two hard drives, and if either one of them fail everything is gone, giving you twice the chance.
You need to decide WHAT you need from your disk subsystem.
If you're going for high uptime, use RAID 0+1.
If you're going for high sequential transfer rate, go for RAID 0.
Neither RAID organization will improve random I/O times much, so you won't see any significant improvements in starting programs or booting your system. And RAID is not a substitute for backups.
RAID 1 will give you as good or better read performance, depending on how smart the controller is. Writes will be slightly slower - each write has to be done to two drives, although they can be done in parallel so performance isn't as bad as you might expect.
it may be naming, but you get better redundancy, and great speed, with raid 10 (or 1+0). Mirror A with B. Mirror C with D. Then stripe the 2 arrays in a raid 0. This way you can have 2 drives fail (1 in each set) and still be up and running. If 2 drives in the same set (ex C & D) fail... oh well.
RAID 1 is also fast and safe. Personally, I'd do separate RAID 1 arrays, 1 could be OS, 1 for data. Back up from 1 array to the other, plus externally, and you're GTG.
RAID 10 gives you incredible IOs per second. If you're doing heavy database work, it's the only way to go.