Regarding the position of the windshield fore and aft, I would suggest that you might want to position it so the curve approximates the location of the leading edge of the whing so the wing root fairings will be smooth and small. The LP windshield I fit on the Series V, I am helping with was an early version and didn't fit well. As a result the fairings - currently working on them - are not ideally shaped.
Back to the heat thing, It apparently is possible to tweek the acrylic windhsield with heat as the quote below is from the LP folks. As we were installing the windshield on the Series V I have been helping with, problems prompted a fitting question to LP and this was part of thier reply. A note - We didn't use the heat gun as we found another way to correct the problem we had. So can't give any tips there.
I can talk you through using a heat gun to bend the acrylic slightly to fit, however, the acrylic has a memory and it remembers the flat sheet. It may do some forming that you do not want, if it is overheated or improperly heated.
Lowell