A few questions about suspension, tires, and brakes.

[supmet]

So far I love the Yaris, but the stock suspension and brakes aren't cutting it. Driving on bumpy freeways can be scary at times. I only have 60000 miles on my car, and have gone through 4 sets of pads, turned-replaced-turned-replaced the rotors, and they are shot again. My pads don't wear out, they glaze over(about every 10k-12k miles) and then warp the rotors.

I have a stock 4 door automatic yaris with no ABS on stock 15s (steel not alloy)

Handling-
1) Is the TRD suspension set and sway bar pretty good? Are there better options for the yaris?
2) The TRD set doesn't come with springs - do you have to use the lowering springs? can you use the stock springs? if I use stock springs, will I still see an improvement in handling?
3) Bigger wider tires will obviously increase traction, and therefore handling. My question is, at what cost to gas mileage? I've heard people say you can get better mileage if the wheel is lighter, and other people say the increased friction automatically means worse mileage. I'd like to hear from some people with 16s or 17s on their yaris and what kind of difference they saw in mileage. I'm willing to sacrifice 5-7 mpg for stability/handling.

Brakes-
4) I haven't seen any performance brakes for the yaris - anybody have some that work for them?
5) Are there any brake vents for the yaris?? If I can't find affordable brakes I'm thinking some air flow might keep them from overheating and glazing.(I'm half tempted to cut a hole in the fog light space and run radiator hosing to the brakes )
6) I have drums in the back - would it be worth it to change to discs? I know the fronts do 80% of the work or more, so I'm kind of thinking not really.(but if I put rims on I'll probably change to discs anyways.)

I'm not looking to take up canyon racing or anything, I'd just like to feel comfortable pulling an emergency lane change at 70 when a couch falls off the truck in front of me.