I have asked the coders to take a look at it. FS2 seems to suffer from lag effects more than most games I've played, even when the ping is relatively low. As far as the primary weapons go, a partial solution I had in mind was to have the lead indicator account for it, as described
here.
One option may be to use a kind of hybrid server/P2P system, where some calculations are done on the client end. Descent 2 is like this for example, and the lag was not that much of an issue in that when we used to play it (and when it did come up, it was the same for everyone). However, such a thing may be difficult to add in and has a number of other disadvantages.
Actually, the funny thing was that even I was getting lag-like effects during that dogfight we played, like ramming resulting in instant death and ships jumping around too fast to aim at.