Hey Stoddart Music,
Can I check what bank provider you are with?
For the old transactions, you will need to batch tick and exclude those from the for-review tab (batch actions > exclude selected).
Apologies - the chart of accounts is only a feature on QuickBooks Online. You can search within Transactions for date or amount at the top of the list, so while reviewing the transactions, search for either the date or amount and check if it is a transaction you have already reviewed and added.
The feed will only automatically refresh once a day - you will need to manually select refresh if you want it to do this at any other time. There have been recent changes in the regulations around third party connections to bank accounts which limits when QuickBooks can automatically update without your manual input.