1.

You have many errors in a bank statement imported. EG because you imported comma decimals instead of full stops.

There are too many so you would prefer to delete the statement and import afresh.

I dont see an audit problem if is a manual import anyway.

2.

Alternatively, you should be able to amend the amount if it is a manual import.

From the audit integrity point of view once you are manually importing you may as well allow amendment accompanied by an explanation.

Perhaps until reconciliation after which amendment could be disabled.