For the oversized thumbnails, just scroll the mousewheel while hovering over the Tiles bar, or click and drag an empty space on the bar to force it to redraw. Kind of annoying sometimes but also easy enough to fix.
Left and right mouse-wheel clicks to navigate backwards and forwards in a folder portal's directory history, as in windows explorer or most web browsers. Or at least a left wheel click to move "up" as though you had clicked the arrow or hit the backspace key. For mouse-heavy users, that up arrow is a moving target based on the length of the current directory's name. The wheel click sounds easiest since there's a binding for that function on the backspace key already, but honestly I'd settle f