No, it will not cause issues. Both oil weights are in spec.

Ya, she’s toast. New engine time for sure.

It’s a touch high but not crazy. I’d see what other shops are offering. Coolant system flushes and spark plugs are pretty routine maintenance things and some shops will have specials.

I doubt it’s because you drove off to quick. Could be as simple as the gas cap being screwy, but it’s likely an issue with the evap system. Could be a stuck valve or an issue with the evap line. This is a pretty cheap and straight forward fix but can be a pain to diagnose sometimes.

There are plenty of guides and youtube videos on how to check the evac system for issue.

Are you sure he said CPR replacement? Do you have an estimate with the parts and labor broken down? I’m unaware of any part on an elantra called a CPR.

Without seeing the issue there is no way to know what’s going on. Try to tighten the hinge bolts to spec first and see if that fixes it. If it doesn’t, come back with pictures or a video.

Jfc. Don’t do that. Just replace the brake pads.

There are tons of things you can cheap out on and it will make no difference to your life. Brakes aren’t one of them. Buy an OEM or OEM equivilant.