Can't speak much to most of your complaints (I like my keyboard heavy, planned to change all the keycaps and switches, and didn't get a wireless keyboard), but you can download an offline version of Via to configure it. https://github.com/the-via/releases/releases
You said you'd like an offline flash update & macro programmer to not depend on cloud-based software, and that exists. Keychron hardware runs on open source firmware and is compatible with VIA as well as their proprietary Launcher. I just checked on my Q11, and the two softwares are basically the same.
