Yes, Nokia 7 Plus does have the OTG support.
Yes, Nokia 7 Plus does have the hybrid sim slot. You can use either 2 sim cards or 1 sim card & 1 memory card.
Yes, Nokia 7 Plus in-the-box accessories include a pair of an earphone as well.
Yes, Nokia 7 Plus is made of series 6000 Aluminium.
Great battery life, immersive display, solid design, and software at its purest, that's the Nokia 7 Plus for you.