I've never made a poncho liner UQ, but I don't think you did anything "wrong". If so someone who has can point that out.
I think now you're at the point where you need to dial in your suspension. Due to all the different variables in individual setups (hammock dimensions, RL length, UQ dimensions, body dimensions, shockcord strength etc etc) the chances of getting it hung perfectly the first time are slim (IMO).
It took me a while and a few trips adjusting things here and there and modifying the suspension on my DIY UQ to give it that perfect fit. Now that it's "dialed in" I just attach it to the hammock, make a few small adjustments here and there and it's ready to go.
I'll +1 FLRiders suggestions:
For the cord across the head issue, you can change the angle of the shockcord to a more comfortable position by a couple of different methods. You can try using a small biner on a prussic attached to the RL (https://www.hammockforums.net/galler...&cutoffdate=-1
) , and Triangle thingies made from mason line or other light cord http://www.arrowhead-equipment.com/u...9_orig.png?371
And there's probably other ways out there I haven't tried.....yet.
Try a few and see what works best for you. You may also want to look at the Leighlo suspension - it's up next on my list of mods. http://www.hammockquilts.com/techinfo.htm