I think I would have the center of the tube exit the transom close to 3/8to1/2 in. above the bottom of the keel and parallel to the keel as you said before.It looks like youmight have it a little high.If you run it parallel like you have it, it has a good chance of cavitation by not having enough water to bite onto. You basically want one blade of the prop in the water while on a fast plane. You can put a straight edge along the running surface and back to the prop to see about where the prop will be in the water and see what I mean.

Your rudder looks good just as is. I'm not sure what you mean with the deg. of turn, but as long as you have decent rudder travel in both directions without interfering with the prop, it should be fine. Oh, I just saw you have it centered behind the prop, yeah, carry on with Simon O's instructions. He's right about these boats not wanting to turn left until you slow down significantly. ...and it'll do better on the right as far as speed goes.

Hope that helps.