fortunately brake pads are very easy to change, and make a huge difference, you've already done mods 2 and 3 which are fluid and hoses.
if you plan on doing a few trackdays and budget can stretch to them I'd recommend Performance friction PF08 pads - done 5 full trackdays on mine and they're probably less than half used. plus excellent, fade free stopping power.
Other useful thing to do is remove the front fog lights, and the access panel flap behind them. your model year zed has no front brake cooling ducts, which means things get a little hot!