Fair enough! I appreciate the replyBigger fins may help (our larges are a good choice because they have some flex/spring in them) but it sounds like you might be better off trying a board like the Phantom, since it is better suited towards the average surfer (guessing from your own words) and also more average waves. The Shadow is a high-performance board for sure, and not always the best choice if your surfing is at mid-range.
I did debate a lot between the phantom and shadow before getting the shadow. I wanted something more in the vein of a traditional shortboard, and I thought it might be better for the steep beach breaks I mostly surf. I only grab it when the waves are good, although good to me and good to a Hawaiian might be different!
I guess it's hard to objectively evaluate one's own skill. I know how to surf and I've been riding shortboards since I was a kid, but I'm not in danger of going pro anytime soon