New DocType and link data on forms

Hello everyone, I have been using ERPNEXT for a bit and I really like it. I have a few questions.

1: if I create a new doctype within the app, will it get deleted during an update?

2: how can I link data from a sales order to a work order?

3: how can I have a work order with more than 1 product?

4: how to print completed work orders with the bill of materials used as well as hours of operation>?

5: can I create a work order without the bill of materials, an example. just labor.?

Thank you for your help, I hope you guys have a great week!!