For start, docman uses cascading style sheet which is located at distribution
directory html/docman.css. If it's left there, docman.php will serve
it using docman.css?STYLE=CSS. However, if you move it to
Apache DocumentRoot (
see directory layout) if will get it from here (and enable browsers and/or
proxies to cache it).
You can enable it using ln -s as described in installation instructions.
Trustees are compiled on-the-fly into php code and store in file on disk until next change of trustee file. Since it's just included in most times, it's a great save our of time, but it would benefit anyway from some kind of PHP acceleration (like Zend Optimizer or APC).