1. Faster loading times and, with to no moving parts, zero vibration. I'd go for a 240GB or 256GB SSD for my Windows partition and most commonly used programs, then pair that with a 2TB HDD for music/movie/game files, etc.
2. My build cost me around $700-$800 to put together, minus monitor. I don't have any gameplay vids, sadly, but I can tell you it's a pretty fast machine. I just need to swap the current R9-270X for a GTX 970 and it'd be golden for the next 2 to 3 years.
3. [redacted]
4. Only open-source versions like OpenOffice, which worked pretty well for me back when I couldn't get my hands on a copy of Office.
5. WIndows 7. Ironclad compatibility with games and none of the wonkery associated with Metro.