Regarding MPlayer and audio delay problem. I myself don't have any video with such issues (converted to mpeg4+mp3 and stored in avi container) to experiment with. Audio output module which uses gstreamer is not quite reliable regarding audio/video sync and there seems to be quite troublesome (if even possible) to implement it in a correct way, but at least it is not so bad in its current form. So providing a link to some video sample with this problem at mplayer garage trackers may help to investigate it (well, I think, I'm asking this a third time already with no reaction, does it mean that people are not that much interested in a correct audio sync even without manually tweaking it? ).

As for audio delay settings for those who need it, thay can be added in OSD menu in the next version. Also I think about remapping '+'/'-' buttons to seek +-10 minutes instead of current audio volume control (volume can be changed from OSD menu even now).