If you scroll down on the landing page, there are tons of cases with blue bars only going in one direction; I think the distance between the numbers and the bars is quite reasonable there. When I speak of red bars, I assume that there is a red bar of significant size somewhere down that column, resulting in the space here. That said, I would agree that this is not necessarily the best visualization to begin with; I don't think I would use it at all.

The entire "Line items" subtable is indented: its internal horizontal lines do not stretch all the way to the vertical line at the beginning of "Line items". However, the horizontal lines between the line items for different orders do. This subtly highlights where one order ends and the next begins; I think its quite clever. Also, the "Qty" could be made thinner if you wanted. But in the screenshot there is still space available to the right, so its not vital. (Also, there might be a three-digit Qty further down the table, which would make this the right width.)

I don't find the "Folders" side bar that vital and I'm sure it could be improved. When saying that I think the interface strikes a good balance, I'm focusing on the main view. However, I think that there could be extra root-level items if you add further data sources, and I also think that you can make the sidebar thinner, at which point you will only see Cat, Cust, etc. For a main screenshot having the full names visible does seem cleaner, though. (I'm not entirely sure that all of this is correct. I cannot test it--unfortunately, while I think that Ultorg is very smartly designed in many places, its license cost is not justifiable for my limited use cases.)