Well I have 2014 corolla le I know it's not a big race car to start off with. But I hardly see any fixed ...and I recently increased the exhaust pipes in size and removed the resonator and have a super 10 flowmaster at the end so basically a thick straight pipe all the way to the cat converter.

Baloney. Changing just the muffler without changing the throttle body and camshaft will get you NOTHING. It's air in and air out. If all you're changing is air out, how do you expect that to improve performance. ...? And don't say it'll drop backpressure. Because camshaft timing needs a certain level of backpressure to perform properly. Reduce backpressure and you'll actually lose performance at higher RPMS due to valve overlap.

Yes it will but not enough to notice.

nothing that you will notice , maybe at best 1 or 2 hp

Yes