Just FYI. apt-get autoclean would just clean the apt archives under /opt, and apt-get autoremove alone without other parameter would not remove anything at all.

Mine has just 38.2M and the system is running stable and battery healthy.

I guess you might have worried that the system requires considerable space in rootfs for temporary swapping. In fact, there is already a swap partition in place for memory swapping, and other the temp storages have already been seperated from rootfs after PR1.2.