It would be handy to see by looking at the windows toolbar (there is an appropriate Mac equivalent) the percentages of transfer completed when the app is minimized.

Thanks.. This is a good idea.

Not only would it be nice to have this information when minimized but also when opened.

The left pane where you are showing the current file upload percent and xx of xx. It would be nice to see how much is left total. For instance, I have a directory that I like to backup. It is 1g in size. I have no idea how much time/% is left.

Yes that is really necessary.
And please for BucketCommander as well. A new line with the transferred data every x seconds would be fine.