If a iPhone repair shop (that isn't Apple) opens & replaces your phone battery&that. Does it come back exactly the same as when you bought it?

Just I swear last time I got something replaced the screen sits a fraction higher up (so the phone is a tiny littlebit more thicker then before) is this true or no?

There would be slight differences as they would not be trained the way apple workers are

Depends on if they use Apple replacement parts and how good the techs are. I know Apple users that had to get Apple repairs done several times to fix the original problem, only because the resulting "fix", looked like it had been fixed by someone other than an Apple repair tech, but in fact Apple was the only one to touch it.

Well its not a guarantee in that case. They could mess it up, more likely wouldn't or it wouldn't be exact exact, but as long as it is not way off & it works as it should I wouldn't raise too much of a fuss.

They wouldn't be able to get the screws in if the phone wasn't flush. I don't think it changed, but you could always compare it to a new iPhone in a store.