3) Hand binding is a possibility, I know as I've done a couple of my own bats!
5) If you are prepared to spend a lot of time sanding I think you'd be able to get about 2 oz off, but that may take a while by hand! As for the sanding itself, start with a rough grade of paper (100-120) then work your way up the grades to a fine sanding (about 400 to finish). Do each grade of paper until the bat is consistent all over, and most importantly don't skip grades as this ruins the finish.
1) an oval handle doesn't rotate in your hands as much as a round one on striking the ball (and feels nicer in the hand!)
2) I think the whole handle is made from carbon fibre rather than putting some in (don't quote me on that though). The grip and splice stickers cover it up so its only illegal if you get caught!
4) probably irrelevant to be honest, use any bat and you'll get used to it, by angle I'm assuming you mean bow in the blade? This occurs naturally over time and use anyway I think.
As you'll notice I answered in no real order. The later I responded the less certain I am of my answer.
Hope this helps