The first semi-secret is the playboy magazine at the start in the draw:

The safe vent fan part (the one on the left if you was facing forward):

The next secret is breakable glass at the top of the glass doors:

Use the chair for a boost up:

Outside there is this button:

Which opens up this:

A breakable box for people who don't know:

That concludes the secrets and tips of Esk_Escape.