fit the swaybar mate, should help definitely. also look into some cheap but decent coilovers like BC. the cars not going to go particularly fast but you can make it handle very well and when driven properly, still embarrass people in the twisty bits.
good on you for looking properly into the handling of the car. your starting in the right place for modding.
i agree with most people, that exhaust is designed for a turbo engine where the turbo is dampening allot of the noise from the engine and the huge diameter is *atleast could possibly be* needed for the exhaust flow. on an NA is is grossly oversized.
the noise may be to your liking and in that case, cool, but i dare say after a while the drone, bark/farting, and general awfull noises will do your head in. i suggest have a listen to some better options and make a more informed decision. that being said, when i was a p,plater i made all the same usual bad choices