Main Sheet Traveler Location
Seems to be highly dependent on weight. At 6'-3", 215 lb, I am almost always centered on the traveler upwind. The light guys seem to travel out almost as soon as they can trap. Some even before. I know that I personally can not point anywhere high enough if I travel out...just can't maintain the same angle upwind.
Also depends on how much downhaul you use. I use the downhaul as my primary means of depowering and I'll typically bottom out the downhaul blocks before I'll consider moving the traveler. Tightening the downhaul bends the mast and opens up the leach. Some guys tend to leave the downhaul on the loose side. This causes the leach to stay tight so they must travel out to compensate.
Upwind Sailing Position (Center, Forward, Rear, Always on the wings, etc)
There is no set upwind sailing position. However you try to maintain a set hull trim which is windward hull flying, leeward bow about 1/2 way underwater. So you start out sitting pretty much on the front crossbar in the light stuff. As wind and seas increase, you move out and back to maintain proper hull trim. You don't want to be sticking the bow under too often and you don't want to be doing a wheelie.
Pull it snug enough to take out the wrinkles and then give it just a little more. Your primary sail shape adjustments are the mainsheet and downhaul.
Is there a forestay adjustment?
Someone might have some actual rake measurement numbers, but basically, you want to be raked back about as far as you can go. This means that in high wind, fully trapped you will have no more than about 2 inches between your mainsheet blocks. The rig should be loose enough that you can easily rotate the mast beyond 90 degress downwind.
does the H17 sail directly downwind similar to a H14 or does the boat like to reach a bit?
Not directly downwind, but deeper than boats with a jib. Put some streamers on your bridle wires. Downwind these shouuld point forward of 90degrees- probably around 100 to 110 degrees. As the wind increases, you can head the boat up slightly and use the increase in apparant wind more to your advantage.