I agree with all the deletions of the themes for space reasons.
Actually, I would agree with the removal of ALL themes except for a default one. This would show maximum space savings yet provide basic funcationality.
One thing I would like to see is the ability to point to a directory on the network to load the theme instead of the current "custom (ext/custom.css)" that we currently have.
For those of us with USB ports, it could be a simple point to the CIFS mount to load the info. If you do not have a USB port, a simple point to a network share and you can get the data.
A simple check on the availability would be needed. If it was not available it just defaults to the default theme and you can still use the router till you get things sorted out.
Yes, I know I could just copy the theme into /www folder after each reboot, but then I am taking up space in RAM and making scripts and such. With a browsable/definable location it would just load it every time it is needed.