Currently, it is impossible to open any Goto menu while the find feature has focus. To my knowledge, the control key serves no function while the find pane has focus.  Pressing Control-P, etc should open the Goto bar, but does nothing instead.

Conversely, you can open the find bar while Goto is open, but it leaves the Goto bar open. 

Additionally, using a Goto-specific shortcut will close a current Goto bar, rather than switching to the Goto-specific variation.

I recommend that any opening any Goto, Find or Replace bar would first close any existing Goto, Find/replace bar. Much like the Replace bar closes Find and opens Replace and vice-versa.

Additionally, I recommend that the shortcut commands that open a searching feature (goto, find, replace, etc) not be used to close the feature.  Sometimes collisions between using multiple search features put you in a state where you think you're doing a Find, but you've actually just closed find and are now typing your search into the file you're editing, etc.  Escape is a good universal way of exiting a pane.

I belive I found a typo in the ST3 API docs:

set_async_timeout(callback, delay)

should be:

set_timeout_async(callback, delay)

It would be nice if you could organize the currently open files in folders or group them together in the upper bar.

Sometimes I need to work on several projects, i.e. to get some source code from one project to include in another.

This feature would help you to stay organized and have an overview over all of the projects you are working on.

The feature could look something like this:

Maybe this feature could also be included into the side bar: