Hi,
You will be able to synchronize Inventoria and Copper or Inventoria and Express Accounts, but not the 3 modules simultaneously. It works as you mentioned, you manage the items/products inventory on Inventoria and sell/invoice either with your point of sale(Copper) or Express Accounts. The synchronization is meant to reduce/extract the amount of items you have sold from the Inventoria inventory list, that´s about it, nothing else is synchronize.
If you wish to run a Sales report you will use the software that you are using to sell to run the report, either Copper or Express Accounts, remember that you are not selling using Inventoria.
1) I can't find any record or report that shows the transaction of the withdrawal of inventory.
This is not an option, Inventoria will only show the available/quantity items remaining, however you can run a sales report from the other products to review how many items you have sold.
2) There is no record of any activity in Express Accounts of the Inventory receipt or usage.
This is shown on the "View receive history" tab from the software left side column bar,