What theme are you using?
If the theme author hasn't coded it in there, it won't be there.
If you've coded your own, then you've missed out the %pc (current playing time) and %pr (current time remaining) tags, take a look in
Theme Tags - Playlist/Song Info in the manual.
Regarding Hotkeys, I find the manual to be perfectly clear:
HotkeysHotkeys are shortcut keys for use in the File Browser and WPS screen. To use one, press Rec within the File Browser or Rec within the WPS screen. The assigned function will launch with reference to the current file or directory, if applicable. Each screen has its own assignment. If there is no assignment for a given screen, the hotkey is ignored.
The default assignment for the File Browser hotkey is Off, while the default for the WPS hotkey is View Playlist.
The hotkey assignments are changed in the Hotkey menu (see section 8.10) under General Settings.
WPS Hotkey.File Browser Hotkey.
These options set the hotkey function for their respective screens (see section 4.5). The default for the WPS is View Playlist. The File Browser default is Off."
In short...The hotkey's function is selected in the hotkey menu in "Settings - General Settings - Hotkey", there are two individual hotkey settings for the two areas hotkey can be used, the Filebrowser and the While Playing Screen. When fired, the hotkey will perform the selected action for the current screen.
EDIT: If I read correctly, perhaps you are mistaken? There is no way to display the current/elapsed play time in the while playing screen conditionally via a setting*. It is either in the theme you are using, or it is not.
*On a side note...A clever theme author could achieve toggling their display by setting/incrementing/decrementing a variable linked to a touch area...but not via a setting (at least not a setting for this specific purpose).
[St.]