it is not non standard. When in explorer You using keyboard, also the text is with fully highlighted background. Not inverted like TC, but anyway with dark background and light text. It helps a lot
That's something different. The dark background in Explorer is not selection, not for focus. In Explorer selection moves by default with focus. In WinSCP and TC is does not by default. Note that if you force focus to be moved without changing selecting in Explorer (by holding down Ctrl key while pressing arrow key) you will get the same results as in WinSCP. BTW, You can switch to Explorer style behavior (move selection with focus) in WinSCP preferences.
because i use for editor PSPad (because of highlighting -- do all nice tools comes from Tschechien?) and it starts slower than your editor. So for quickview i would use yours, for editing PSPad.
You can have more editors configured in WinSCP.