Loud noise if i hit the gas to hard in reverse

Make sure that your axles aren't broken. If you have a broken axle the power would transfer to the wheel with the least amount of resistance (to the broken axle) therefore not propelling the vehicle. Also look at your fluid level and condition. It is possible that the transmission is slipping in which case you'd need a transmission/rebuild.

check the magnet on the drain plug in the diff and if you find metal it will be the big taper roller bearing failing on the pinion.

Did you install the brake pads the right way?

u-joint is rusted

Go with a completely damaged & blocked exhaust converter

Air In --Air Out Yours doesn't go out & the trans gets confused
& can't use the shift strategy it was born with

That is the 30 mph or a gas filter really clogged,not real likely

What is with the noises?

Turning & just sitting still?

What was the trans shop diagnoses,was it test driven
& did you go alone,have to do that

Your car --so your part of the solution,be proactive

check the sway bar links

You may try checking for slack in pulleys such as alternator, power steering, water pump, etc..have heard similar noises when pulleys vibrate from a bad bearing.

Sounds like something loose is swinging with the stop and go momentum. Look underneath for something loose, like exhaust. Have someone listen close by while you drive it slow in forward and reverse, to try to pin point it.

Replace the IAC valve.