I'm not sure (not the author) and I think syncing config is a lot more difficult than it would seem at first glance. Eg Panel Layout: Imagine syncing between a multi-monitor-setup (work PC) and a single-monitor-setup (Laptop) - how's that supposed to work? The panel might be on the second screen on the PC, but once synchronized to the Laptop, that would mean either
- missing panel (off screen)
- double panel (stacked on top of each other)
- hidden second panel (one below the other)
- ...
Syncing .config would (at first glance) work best for device independent settings (e.g.: Indentation in Kate with Tabs vs. Spaces) - but even "fonts" in Kate might already not be a good idea, as a font might not be installed in both systems (and it might get worse with font-sizes, scale-factors...)
I don't think many of those removals will have any impact on power consumption - at least not unless you're using them right now. Removing a non-default task switcher (if you don't use that currently) or theme (e.g. "Plasma Air") will help with maintainability of the code and more time for other work than hunting down issues in that task switcher or theme, though. This might result in freeing up time to work on other stuff. So, indirectly: it's possible.