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.
No. Nokia 7 Plus does not have a dedicated memory card slot. It has a hybrid sim slot. So, you can use a MicroSD card and a sim card at one go.
Yes, Nokia 7 Plus does have the headphone jack, which is located on the top panel of the phone.
Great battery life, immersive display, solid design, and software at its purest, that's the Nokia 7 Plus for you.