Man, i think you don't have to memorize all cases because you can be fast also using the intuitive f2l(like me, in fact using it now my average is about 11/12)
However i can say that there are some difficult cases in intuivie f2l, and for these, you need the algorithms.
when you improved your intuitive f2l, you can see that you can solve almost all cases as the algorithms.
7-8 moves... I will work on that. Thanks my f2l move average is around 42 moves... I should prolly shoot for 32-ish then eh? Also do you have a good H-Perm? Mine is slower then hell...