Can you change the budget or account codes?

Not until Change Ordering is implemented (over 10K process). Then you will be able to do this IF the order is not completely invoiced. You can always do an expense tranfer in MyFD to move the money to the correct budget. If the budge is bad (i.e., closed after the order was placed but before invoiced, you can contact AP and they can change it to a good budget, but this is the only exception.)

Does the system support change orders?

For this rollout which only supports non-catalog orders for under 10K, there will be no "Change Order" button. To change an order, the user who placed the order must contact the supplier and add a comment to the EI Order stating the order is regarding the change. If it is simply a price difference (line item description and quantities stay the same) and the supplier is OK with shipping and invoicing at the new price, it is OK to use the same EI PO number. Add a comment to the EI noting the price change.

Does Non-Catalog Ordering provide basic order confirmation, ship confirmation, cancellations, back order notifications, etc?

For Ariba Enabled supplies only, there is the ability to force them to send order and shipping confirmation. If they are set up this way, then they cannot invoice until they send the confirmations. However, there are no timing guarantees. Ariba trains suppliers to set a field to force  sending the Order and Ship Confirmations before the invoice can be sent. Again, there is no way to force the supplier to send these in a timely manner. All they have to do is send them before the invoice.