I have tried similar ideas but then you don't get access to the pinky.
There is no doubt in my mind that if CH swopped the castle 4 way position with the 8 way above it, the result would be much more user freindly. Alas that would be a change and I don't see it happening because that is one thing against CH, a reluctance to change!
I use the Prothrottle 8 way for views and the castle on the stick for the up / down view element. My eightway on the stick has just four keys set to it so I don't use the diagonals at all.
EDIT: Your post did prompt me to make the comment about swapping the castle and the eightway positions with CH Products. The more that do may get them to change sometime in the future.