For some reason, I read MacBook Pro non-SR 2.16GHz, maily because most of the non-SR MacBooks I've met have been 2GHz or lower, of course that's because most people bought the bottom model, so sorry about that
1. Your maths are slightly eschewed. 2.16x2=4.32. 1.8x2=3.6. 4.32-3.6=0.72. The difference is, as I stated, 720MHz. There are very few, if any tasks, where the difference between a 667MT/s FSB and an 800MT/s FSB will cover this clockspeed difference.
2. You are correct. As I stated, I misread your previous post.
3. Your understanding of the hard drive industry is laughable. Yes, a PMR 4200RPM drive is probably as fast, or faster than non-PMR 5400RPM drive. However, 1.8" HDDs are comically slow. Their seek times are absolutely dreadful, and continuous disk-to-buffer transfer rates will never come remotely near a 2.5" HDD of the same spindle speed. Have you ever tried booting off an iPod? It doesn't matter how much cache you put in the drive, it will never cover such dreadful physical disk performance. Hybrid drives would probably be a tremendous improvement, but Apple aren't using those.
If you want to flame somebody, flame yourself, sir.