Samsung Galaxy S7
Unlocked

Does this phone work with Metro PCS, i read some phones that are unlocked might not work with certain carriers still.

I haven't personally tested it with Metro PCS, but having sold over 140 Samsung Galaxy phones on Swappa, more than 120 of them factory-unlocked, I am yet to encounter a buyer protesting that a GSM SIM card wasn't compatible with a factory-unlocked phone. The scenario you allude to may have occurred when an unlocked phone had a Google lock activated (as automatically occurs when any Android phone is factory reset without first removing any owner email accounts).

Incidentally, I happen to have a Galaxy S8 G950U Metro PCS phone being sold at a discount after a buyer's funds didn't clear. Here's the url in case it suits your budget.
https://swappa.com/listing/view/LRLV17779

Can you post a pic of the screen burn?

It's not really possible to see it. I just posted a picture taken right now under bright lights of a mainly white screen. I only mention the possible extremely faint almost invisible screen burn to avoid a supermeticulous buyer seeing a possible shade and saying there was a failure to disclose. There's really next to no screenburn or ghosting or shadow.

Do the scratches on the back glass affect the photo quality?

No. Not at all. The thing is that unless a device shows absolutely no signs of prior use, it cannot be classified as mint, and the seller has to disclose the defects or damage that preclude it from being listed as new or mint. So, since there are very faint scuffs or scratches which are nevertheless detectable by a buyer upon careful examination, those cosmetic defects have to be highlighted. This phone has 100% functionality.

Would you take 160 for it?

It's an S7, and would be below my cost once Swappa's $10 fee and PayPal's $6 fee are deducted, and even before my mailing costs. Last night overnight, I went through all my listings and cut each one to just above my cost, to sell as many before Christmas. So, the most I could take off this would be $4, and at that point I made zero profit but hopefully get 5 stars out of it.

Ok... and does it cones with the original charger?

No. No chargers at all available. I can throw in a new, highly rated USB cable as a bonus. It's rated tops on a major online site, and I use it myself and rate it ahead of Samsung OEM cables.