You really want to run a total loss electrical system and bump start a high compression V-twin? But didn't mention re-freshing the engine on a 19 year old machine?
Skipping brekkie once in a while would net the same weight reduction gains. There isn't much to reduce weight on a Buell. You can add a little power, big bore kit, real tuning, and depending on the track, a XB9 primary would gear you lower. But still... why? It would be more competitive in a SuperStock than it would with the modded bikes in Superbike.
A Buell makes a great track day bike. Not much to mod at all TBH. No coolant to swap, no chain to adjust, no valve lash to check.
IMO, don't lose sight of your goal, which is to win a Track Day right? So get faster. Get
training. #1 get training. Did I mention to pay for some quality education? Because you should pay for some professional training.
For the bike, get better brakes (SBS or Brembo pads, ZTL-2 caliper, 19mm radial master, EBR rotor hardware) at a MINIMUM.
Get better suspension, Re-build the forks (they're decent at mid-pace) and have them set them up for YOU. And get a NEW rear shock, yours is toast.
Get better tires. New tires are awesome, pick your brand, don't go cheap.
Sure, get Racy McRacer plastics that look good to the Missus in the garage, take off the headlights, brackets and bar switch, kickstand etc. You'll want much lower bars Renthal RC lows are great, or find a "R" upper triple for clip-ons* (I have one if you want it) it will fit because you removed the headlight shell.
Remove the dash, and get an AIM Solo 2, remove the key and get a woodcraft bypass, get adjustable pegs/rear sets/levers.
Broke yet? Welcome to the track
Edit:* Oops, I mis-read it was an S. The R should already have clip-ons, but they do that weird 'tiller steering' thing. Universal fork tube clamps can make them right.