I wouldn't trust any other sellers than OnePlus themselves.
Yes he's right, the only phones that require the carrier to push the ota's are devices that are carrier locked which happens a lot in the US, idk about China but here in The Netherlands pretty much every phone is unlocked no matter ho...
Could you add shelf to the mod? I hate it being white while the rest is black/grey
design, me and my friend both have it and it's in the renders on the OnePlus site as well.