the 18mp sensors in canon 7D, 550D, 600D, and 15mp senors in 500D and 50D, all have little noise even at base ISO 100, but your boy and dinosaur samples have more noise than i would expect at ISO100.
lack of sharpness is due to 18-200, its not sharp enough to give u anything above your 40D, dont forget to throw it in the sea with your 7D
if u r looking for ISO kings, Full-frame is the way to go, 5d mk2 or d3s/d3x. FF are also easier(sharper) on lenses.
FAT32 cannot eat away 6GB. try it on different cameras or get similarly priced lexar premium/platinum 200x 16gb cards, mine fills up all the way till 14.5 gb
ps
i almost bought a sandisk 30mb/s card today, but i would stick to lexar now, thank you for the warning!