There's allready excellent advice in the replies, I'd like to put in some more.
The Kat's electrical system is very vulnerable to moisture, be sure the drainage of the spark-plug recesses is'nt blocked.
93er huh? well, you can be sure the sealing of the caps is gone, look at them, they don't seal the spark-plug hole very well now dod they?
I remember I made a rain deflector out of alu plate which blocked the gap in front of the spark-plugs.
She also stood me up once, it prooved to be corroded connectors under the right side fairing the part that's under your butt.
check all the connectors, and treat them with contact spray.
also use non-restistor sparkplugs, your baby really needs those with it's vulnearable electrical leads/connectors, so take the same plugs but then without the "R" you could even try the hotter version, with the & in the type designation.
Performance wise:
Biggest gain would be of course the engine swap, using its fathers (GSXR 750 RR pre-watercooled models) intestines.
or complete engine.
Cheapest solution would be the shorter gearing, yes I know, i't wouldn't get you more power, but it sure feels like it !