In order to get the best up wind performance you want to have the max straight rake in the rig this is achived by have the mast step at min setting (ie as far forward as possible) and the mast as far aft at the deck (mine is set with spar tite) and yes it has to be fixed for the N/A's.

Then you can set the forestay for max lenght. Back stay should be totally loose. With those settings you can follow the tuning guide from your sail maker. I have settings for light (< 10 knots true) medium (8-14) and heavy 14 and up

I only adjust the shrouds not the head stay

That said when we are hard on the wind going up hill the helm is totally balanced (two finger driving) up thru about 13-14 knots

After that the amount of mainsheet trim and travel becomes key to keeping the boat flat and balanced I have never had to two hand the boat when hard on the wind Reaching is a different matter that can be real work

Hope this helps