You're right. I simply haven't had time to implement this. Features are prioritised according to the number of votes they receive on a public Trello board [1]. There's a card for implementing a proper context menu [2].

Regarding Ctrl-Shift-P: I've created a card for this [3]. You can vote on it to have it moved up in priority.

[1]: https://trello.com/b/WpIUiPAd/fman

[2]: https://trello.com/c/wHX5czeT/22-make-it-possible-to-open-fi...

[3]: https://trello.com/c/PhdT0G7v/144-ctrl-shift-p-allow-to-beco...