You cannot add a scanned attachment in TurboTax Business with the exception of your 8453-FE. However, if you have PDF software that is capable of combining documents, you can combine your 1099-B with your 8453-FE (although there is no guarantee that the IRS will process both documents).
Yes it is required to provide the 1099-B statement with your tax return if you only enter the summary.
Yes you are correct, you will not be able to e-file your 1041 unless you want to type in the individual transactions from the 1099-B.
@colombo01
