A:AnswerYes, any Bluetooth headphones will work. The Apple pencil has to be the Apple Pencil Pro. First gen and USB-C version will not work on this particular device, which is a little irritating considering how expensive the pens are. I got mine cheaper than new open box at Best Buy.
A:AnswerI have never attempted this. However, it should work but it would be limited compared to an iPhone. For example, no sharing texts, screens, etc.
A:AnswerThe iPad is available as wireless connectivity only or as wireless + cellular (for an additional cost). The wireless only version can link to an iPhone so you can answer calls coming through your iPhone with the iPad. To use the cellular function of the wireless+cellular version you need a separate cellular account with a cell phone provider.