Fujimo- I just installed mine about a month ago. I was going back and forth on the install as well. If you go over to the RealJetBoat boards there was a pretty good post about it where some very helpful people set me in the right direction and it went off without a hitch. Im no pro, but If you want to email me any questions you might have, Ill do my best to set you straight.
The sealer that Jack at MPD sold me was Sea Goin Poxy Putty. Get the bigger can of it. Its a two part system and starts to dry pretty quick, so you need to be on your feet. I had two guys helping me out-If they weren't there, I would not have been able to do it since the putty started to get thick on my real quickly.
As far as the four degree's thing- I think its more important that the back of the shoe(without shim installed) should be even with the keel of the boat. The front of the intake should rest even with the area directly in front of it, so that there is a smooth transition for the water. This is what I was told to do for my boat-What hull do you have? Is there a delta pad on it?
Hope that helps.