I ordered the new iPad Pro (12.9” wifi), and am holding off on Apple Pencil until I can get it discounted, since I don’t use it much. You can charge the 1st gen Apple Pencil with iPhone.
I don’t even think you can use an older pencil on the new iPad. You paired the old one by connecting it to the lightning connector. Doesn’t have one anymore!
I don’t think the pairing would transfer over. It’s not like AirPods where the pairing is through the cloud and usually Bluetooth devices need to be repaired when setting up as new
Doubt it. I am the last person to talk about Apple as I am not specialist, but I don't think that the pairing will be carried over. If your restart an iPad you have to pair it with the 1st gen pencil. This tells me that this sort of information is not kept anyway. That's how the 1st gen pencil works. You need to pair it manually. There is no automatic pairing like other Bluetooth devices.
If those type of settings were stored in the cloud they could support automatic pairing for 1st gen Pencil too.