jls_legalize: Addressing your questions:
1) Maybe left-side bar is easier for you, but I think this will vary a lot between people. I generally keep my mouse toward the right side of the screen, because many apps now put the scrollbar there (unlike many early X-Windows apps), so for me, the top is usually closer. As we say here in the USA, "Your milage may vary".
2) I agree that there is lack of contrast between the active window title and the others. I have already experimented a bit with the color, and will probably try to make the colors somewhat more distinct. Also, I know some people really like to tinker with the look of their system, so I may experiment with using optional environment variable to define colors for title text and bar background, but have some defaults that provide at least a little more contrast than flwm currently does.
3) Sorry, I don't recall what alt+enter does in the standard flwm. I guess I don't use that right now. What is it used for and what kind of substitute would be useful?
4) Maybe we can have a set of keybindings to resize (and maybe move?) the windows, but my initial goal is to just re-orient the look of the window titlebars.
Also, in general, keep in mind a big goal for roberts is to keep the default WM small and fast, so each proposed new feature will need to be carefully considered, and we may try to simplify and streamline the WM by removing or revising some current features.