When doing a shared installation, symlinking the templates and the plugins is too difficult because the same directory can contain subdirs shipped with s9y and subdirs later installed by the user.
The current way is:
cd plugins && ln -s ../s9y-shared/plugins/*
which results in lots of symlinks.
The better way would be to have
a) a symlink to the shared plugins directory (like the htmlarea symlink)
b) another directory ("plugins-local") for plugins installed by the user
- less symlinks needed
- no manual work required in case s9y ships with more templates or plugins one day (with the current way, you have to create a symlink for the new plugin)
- read-only and writeable directories (from user's and webserver's POV) are better separated
- users can install newer versions of plugins in their plugins-local directory
All this is also valid for templates.