That's very odd about the Windows Experience Index. Silent mode wasn't enabled, was it? There's an Fn key that puts the machine in low power/low noise mode and that probably tanks benchmarks. At any rate, glad it's working properly now.
I haven't test out Samsung's recovery program on the Series 7 Ultra yet, but some versions I've used previously do have the option to both create a USB recovery drive and delete the partition. In general, Samsung really loves their recovery partitions and tries hard to get you to keep it around. Do make sure that your recovery image actually works before nuking the recovery partition. If there's no option to delete the partition using Samsung's recovery app or Windows 8's (usually Win 8 asks if you wish to delete the recovery partition after making a successful USB recovery copy), then you may have to use diskpart in a command prompt to remove it. I'd leave the Intel Rapid Start partition alone (usually found at the end of the drive).
For RAM, just make sure it's a DDR3 1600MHz standard notebook SODIMM. Get a 1.35v module, not the somewhat more common 1.5v version.