i’m assuming no, but is there any way to add creator and Approver as columns on a transaction report?

in a saved search, yes. If it has to be in a report format, your fields are a lot more limited and it doesn't look like this is natively available. You could populate the data in a custom field and then get it in reports, but that seems like a lot of work when a saved search would work just as well with no extra effort.