I think you won't be able to win against x86 in Quake2 based games simply because it's nearly impossible to not run at full framerate with a reasnoably modern x86. You won't get near that performance with 68K, or 200MHz-ish PPC. Framerate counts alot. When you become good at fragging, the framrate will be the decisive factor if you win or not.
I used to have high lag too, before I bought a new modem. Some modems simply doesn't work well with Amigas. Dunno why; both modems were cheapos.
Try borrowing a friends modem to compare.
Also, playing the Q2 campaign and playing deathmatch or on the net are two completely different creatures. The campaign requires some passive sniping, this will get you instantly fragged when plaing on the net.
Sidestepping and turning to circle around corners with a stable aim is an extremely important skill.
Use vulture behavior and circle around lumps of targets (or bonuses).
Parasite on sucessfull players by running after them and try not to get caught doing so. When the others are distracted when firing at the champ, or think they got ignored by the same, then kill em off. When you get confident enough then start killing off the champ too.
