1) Install Samsung Magician.
*Not only does it have firmware updates, benchmark etc but it lets you assign different PROFILES such as "maximum capacity" easily which does things like disable HIBERNATION to eliminate the Hiberfil which can take up several Gigabytes (i.e. 75% to 100% the amount of DDR3 memory you have).
2) Install STEAM, other games, and put media, downloads etc on the HDD. For example, I have Steam installed to :
"E:\Steam" and have
"E:\Downloads" (and folders for "Media", Backups)
3) BACKUP IMAGE:
You should use the free version of Seagate DiscWizard and make a compressed backup image of your SSD. Make an initial copy after everything's installed and working great, then make a SECOND copy later which you periodically replace. Keep that first one in case problems creep into later backups as reinstalling everything is a hassle.
4) about RAID:
In case it's not clear, what you were doing was not RAID at all which is why you had problems. Normally you'd have IDENTICAL discs set as RAID0 for better speed (data striped across both) or RAID1 for redundancy (same data on both drives).
What you were attempting to do as I guess you understand now is use the SSD and HDD together as a "Hybrid drive". Most of the hybrid drives you buy have only 8GB of SSD but use that for the files like bootup files that benefit most from the speed.
As said, it makes no sense to use a large SSD in this fashion since you can already fit the entire Operating System, programs etc on the SSD anyway.
Summary:
a) Samsung Magician
b) HDD for Steam games etc
c) Seagate DiscWizard backup Images
d) about RAID