How much power do you think a 1G has??? Just make sure that your suspension is in good condition and brakes have been upgraded accordingly.
I think you'll find that most of early celicas that have been put into trees had far from standard suspension and this combined with a heavy right foot is the cause of the bent car.
While the standard suspension is not inspiring, it is far from bad and plenty capable of pushing a 1G.
Having said that, any suspension set up that isn't maintained well or isn't designed properly will most likely be dangerous.