That's nice. Did it give you the performance boost expected, or don't you notice the effect?
We don't know what's on your d:-drive. You do, so please tell us. It could be the system recovery partition indeed, and then better don't fuss with it. But for rather unknown reasons we often see that some data is added to it. and then you get that message. Don't do that.
For your DVD-burner: one ATA-slot supports 2 devices (master and slave, so to say) on the same cable. Older PC's came with 2 ATA-slots (4 devices). Modern PC's often only have 1 (2 devices) but compensate that with 2 or 4 or even 6 SATA ports. Again, we don't know what your PC has.
Ever since I did that I get this little note in the lower left of the screen telling me that my (D:) drive is running out of room. I thought that D was only the partition for the stuff that was originally loaded on the PC to begin with? One more thing - I attempted to add another DVD burner where there seemes to be room on the outer box, but there is no other (ATA) i think that's the name for it...cable for it! The power cable is there but no more room for nada?! Are they just f-ing with me???