Nope stock clutches are strong and can handle decent power upgrades. either you ragged on it to hard or you like to ride the clutch or the previouse owner mistook the clutch for the brake
. also what size rims do you have? remember the bigger the rim the more power it takes to make the rims move.
Rims won't have anything to do with clutch wear, unless they weigh a hundred pounds each. Even though they are bigger, that doesn't mean that they are harder to turn, that just means that they won't make as many revolutions over a given period of time as the stock wheels.
Stock clutch can handle more torque than the Celica can put down, so it is strong and reliable if driven right.
It could be possible that your clutch is going out if the previous driver burnt and rode it a lot.
Once it start to give out at higher RPM's, you need a new clutch ASAP. I just got my new one installed, and cost me 300 dollars, but if you have to pay the dealership to do it, it will cost you around 1000 dollars, so get as much out of this clutch as you can.