1. I'd use a generic "lua interpreter" (like the one provided in the
package)
2. In the lua scripts run through that interpreter, they'd say "load
my_extensions.so" (or something like that), dynamically linking to the
functions etc. resources within the ".so".
This isn't possible with the current implementation, right?
No, because it depends on system-specific code for dynamically linking.
For a simple addon that does that for Unix and Windows, see
ftp://ftp.tecgraf.puc-rio.br/pub/lhf/loadlib.tar.gz
--lhf