Apple warrnty

Again, it will depend on how soon you can get your iPhone to either an Apple Store or an Apple Authorized Service Provider. They should be able to determine, whether or not, this is a manufacturing defect and provide you with your options.

It would be a replacement model and designated as such.

Instead of asking "piecemeal" questions, the following will answer anything you need to know about Apple's one-year warranty. I suggest you review it and if you still have any questions, talk with the Genius Bar technician about the potential repairs.

Ref: Apple One (1) Year Limited Warranty

It will depend on what the actual issue is and, whether or not, it will be deemed a manufacturing defect. If only the screen is damaged, it could be replaced with having to provide you with a replacement phone.

Tesserax wrote:

If it is performed by a certified Apple technician, then the water & dust resistance would remain the same.

Frankly I'd say more than likely better since the resistance goes down with time and every time it's tested (like getting wet or exposure to excessive heat) in some way. It's an adhesive seal that will break down. Any service that requires a screen assembly be placed back on requires a new set of adhesive seals. If it's done right it should be at least at the factory specified water resistance, although that's of course never guaranteed.

i think is not my issue..its manufacturing issue

Maybe or maybe not. The Apple technician will make that determination.

If it is performed by a certified Apple technician, then the water & dust resistance would remain the same.

The logic board would be the only thing that’s been possibly used.

New screen, new buttons, just as shiny and fancy as a new one!

Nothing to be sorry about. I just thought providing you with the source should answer all of your questions without having to ask them one-at-a-time.