To answer seriously, most of the time you're probably missing, the hits you see are most likely not cannon shells but rather small caliber rounds.
This is especially true if you're in a spit 9 with .303's - there is a great deal of discussion on the BBS about convergence - what works for me is to set my convergence at d600 for all guns.
Never fire at more than d600 on a target, at d400 place your gunsight pipper so that is grazes the underside of your target.
At d200 fire slightly below your target.
This is for a stable non manouvering enemy. Slight climb or slight turn by your target will mean that you miss.
Try to have a gun solution that places you slightly higher and behind the enemy - not directly on his six, the 30 degree down view will provide a larger target and aiming at the engine will mean that you rake the fuesalage and cockpit if you miss that target.
Don't hose the target trying to drag fire onto him - fire short 10 round burst - no more and then correct as needs be.
Try using the offline drones for practice, come in at various angles, head on, 30 degrees off the nose, below, behind, from above, left quarter, right quarter etc and fire no more than 10 rounds per gun - when you get it to the point that a 10 round burst hits first time you will be sufficiently lethal.
As far as connections in the game - mine a pretty stable and I log in from the UK using ADSL - I do see some warps but not a lot.
Some people once they die alt F4 - the system takes a minute or so to recognise this then when it does awards you your kill.
The key to being successful is to recognise multiple threats and position yourself to deal with them (SA) to place your a/c in a position to obtain firing solution ( ACM) and then hit what you aim at (Gunnery) all take practice - someone can teach you ACM, SA and Gunnery you have to get on your own.
