[Feature request]: hotkey improvements (scrollwheel for volume/group operation modifier key/always visible control)

[kulkatt]

Suggestion

1:option for using mouse scrollwheel for volume control, maybe M key for mute
volume control is very frequent used. And using scrollwheel to change volume could free the user from sophisticated mouse pinpointing and clicking.

2:using Ctrl (or Shift which is currently used) for a group operation modifier key
many operations can both be applied to one video and to all videos, so a globle operation modifier key will make it more convinent and easier to remember.
Also a global operation modifier key make it less necessory to repeated change the sync/unsync setting through the menu, which is a pain if the user alterntes between adjusting one/all video progress bars frequently.
using Ctrl instead of Shift because Ctrl is more ergonomic to be frequently pressed.

3:option and hotkey for always showing video controls
in some usecasese, those information and video control is quite necessary and will be used very frequently.

4:Ctrl+W for close the active video
just a common hotkey for closing one window in a multi-window application. easier and can be pressed by one hand than Ctrl+F4