Actually Dan, I'm a new 5.5 SL owner. I'm not sure how much tuning advice I could give that would only screw you up for a 5.0. To answer you, my rudder nylon screw is out. No weather helm. I was very careful adjusting alignment first and then through trial and error after each sailing run tweaked the rake. It's perfect right NOW.
Be glad to compare notes though. I'm working on simplifying the whole process from set-up to actual sailing to K.I.S.S. standards so my 9 year old son A) doesn't get board with the set-up process and B)can understand the principles of sailing while enjoying the hell out of the speed and thrill of doing the wild thing. To that end I've done a lot of things that racing enthusists on this website will find high treason. For instance, I got rid of the deluxe four way jib sheet adjustment (I can put it back on later if/when I want) to neaten up the tramp and give me one less thing to have to say to him over and over, "Watch out, don't step on that!" I simply shackle the sheet blocks to the tracks.
This week we have engineered (with my wife as sole judge of the safety factor) our methodology of stepping the mast with just the two of use. We utilize a front winch attached to the forestay and the jib halyard attached to the bridle and everything works smooth as silk. (Hey, my wife was even impressed). Now we have clearance to go sailing just the two of us and that is ALL that is important to me. I was given the gift of sailing pleasure by my dad, who died not long after, and I want to pass that on. Plus, if I can take a friend or two of his sailing once a week I'll be doing my part for the sport itself. My wife's father is a retired sailing coach from M.I.T. and he has been grateful for this opportunity to pass on a little of what he knows and to get a common thread to his grandchild. He's almost 80 but you should see the two of them hooting and hollering out on the wire. Big grins on both. My job is just to make it happen, safely and often.
If it's not tuned exactly perfectly I don't much care, quite frankly. There will be time for that.

Good luck and I'll help when I can.
Greg