/escher/plugins is fine. You can also specify your own custom plugins directory.
See the 'app_plug_dir' config iten in admin-config.php and publish-config.php.
It can take an array of plugin directories to search like so:
'app_plug_dir' => array
(
$rootDir . '/plugins',
'/path/to/my/custom/plugins',
),
I have also written a "Vanilla Comments" plugin that integrates
Vanilla forum posts as blog comments. (It is used on the eschercms.org
site). It is an example of a custom model that pulls from an external
database. I can send you a copy if you like.
Yes, but only a single level of nesting is currently supported.