UI Improvements: Tooltips and Summary
At the very least, it would be helpful to have tooltips for the summary and VT buttons, so they don't have to be clicked to figure out what they do. For the summary, while I understand the concern about making the main window too busy, I find a separate window even worse, as it requires an additional click to open then another click to close, as opposed to just having the info immediately and always available, not to mention that it opens in the middle of the screen instead of over or next to the main window. I've seen screenshots of the info included in the main window, and could swear it used to be like that, and I think that's much better. While it would make things a bit more cluttered, by moving some things around and taking care with it, it could be done in a way that it would still look good.
For example, the export/clipboard section could be moved up or down to create a fairly large space that would be adequate for placing the summary in a 2x2 layout, or the "Check against" and export sections could both be moved down so it could be placed between the checksum pane and the "Check against" section, and the summary button could then be removed, making some more space, and also the VT and settings buttons could be arranged vertically to open the area up a bit more. Also, "Check against" could be put on the same line as its text box (on one line or two, as there's enough height to the text box for the label to be on two lines next to it and this would maximize the width available for the text box), as the box doesn't need to be the full width, which would further open things up for the summary.
In fact, I think it could be done in a way that would even provide room for additional quick access options, e.g. either a popup for selecting/changing hash algorithms or buttons that could be assigned by the user to various algorithms that could be clicked to enable/disable each on the fly.