These are simple actions to zoom in and out on the mouse position, while leaving "Options: Preferences: Editing Behavior: Zoom Settings" configured to Horizontal zoom: to Edit/play cursor (or only to Edit Cursor)and Vertical zoom: to Track under mouse cursor. So you can have it both ways- zooming to edit/play or mouse cursors- without changing preferences.
Requires Xenakios Extensions; For some tight editing work on the fly: Edit Cursor position is stored, so you can return it, using the Xenakios "recall edit cursor position" action when finished.
No Key Bindings attached; i use ctrl spacebar and ctrl/alt space bar (with pause reassigned to alt space)