2 Qs: Auto Item Numbering and Inventory vs. Assembly

Two questions today.

1. Is there any native way to auto number new item records? (My gut says no because it's not on the list of records that can be auto-numbered but I was told to seek out side verification so here I am)

2. My Engineering team wants all items set up as assemblies, even if they aren't assemblies.
   My guts says this is a BAD PLAN. We do have a large volume of items that are assemblies which we also purchase as finished goods. Assembly is the correct record type for those.

But there's plenty of items we purchase that are just straight off-the-shelf items from a vendor that we re-sell or consume as-is. I said those need to be in the system as straight inventory items. I was asked to explain why and honestly, I don't have the knowledge to articulate why beyond "please use NetSuite the way it's designed to be used."

Can someone present an argument for or against "all assemblies." Am I over-reacting and it will be fine, or is this the hill I need to choose to die on? (Context: Engineering is the source of most of our item records, and PDM Vault is our "book of truth" for any item on a BOM)