Yes something like termux might be a sufficient addition to "android". Note a standard GNU coreutils build is about 15M, though one can configure to use a multi-call binary like busybox, reducing the install size to about 1M. See the coreutils-single subpackage in Fedora rawhide for example: http://pkgs.fedoraproject.org/cgit/rpms/coreutils.git/commit...
When you 'apt install coreutils' in Termux you get coreutils installed as a multi-call binary to save space. 1556 kB for the package in total (including man pages).
The battery lasted about three hours with heavy use. Standby life was about one week as well. (I still use a perma-docked n800 with 64GB storage Canola to listen to rsync'ed audiobooks.)
I would seriously avoid using the browser, especially with Flash on that device at this point. Also I believe there's only a DoS CVE for SSH.
With the OTG USB, they're still a cheaper alternative to lots of Raspberry Pi projects.
Android used to use it own process-based virtual machine; Dalvik. This is not the case anymore. Now Android Runtime (ART) is used. Applications are compiled to native machine code upon installation. There is no virtual machine.
