Wrt option (2), what do you think of other libraries like wxWidgets or GTK+? At least on Windows, the latter certainly doesn’t feel at all ‘nice to use’ (admittedly a subjective criterion), but I find I quite like programs made with wxWidgets.
GTK+ on Rust is a thing that is seeing a lot of active work (see https://gtk-rs.org/). I think some of the core gnome stuff has even moved over to rust at this point (like libsrvg).
I have used wxlua in the past and it's a seriously underrated feat of engineering in my opinion. It would be great if there were somehow a wrapper for wxwidgets that plays well with Rust, fingers crossed.
I've never used them, but they seem similar to Qt. For whatever reason Qt seems to be the most popular in commercial products.
wxwidgets is unique in that it translates to native gui widgets (when available)