If someone got some clue
1. Does some bodypart take more damage than other?
2. If you're in long distance should you aim higher? Like if is there somekind gravity.
3. If enemy goes left side should you aim left side of enemy instead enemy?
4. Do you use aim only in long distances? I tend to miss alot with aim close/middle distances compared normal.
1. No
2 and 4.
Yes there is Gravity, The Vanilla settings for bows took some getting used to for me though as the Trajectory of the arrow leaves the bow traveling slightly upward compared to the cross-hairs and arcs down to pass through the cross-hairs a set distance away.
This may account for the fact that you are missing at closer ranges, especially if you aim for the head. There is an ini tweak to fix this to a more natural feel though
This video demonstrates the issue
http://www.youtube.com/watch?v=HMMTJta_fPs
The ini tweak is in the description
3. I take it you mean should you lead your targets, if so then yes arrows don't travel instantaneously.