Revised AutoHotKey setup is at
https://stash.reaper.fm/oldsb/1150298129/Reaperkeys.exe
Functions of this version (after a great deal of playing around and deleting stuff which really was not worthwhile) -
Runs Reaper - so all you do is run this Reaperkeys.exe, which in turn runs Reaper, and when you exit from Reaper your keys are restored.
F4 = Show/hide Mixer
F5 = Show/hide Media Explorer
F6 = Show/hide Routing window
F7 = Show/hide History window
F8 = Show/hide Performance window
F12 = Goto end of project, record, insert marker and ask for a marker name. Handy if doing repeated takes at end of project, eg in classical recording.
\ = Record. Or continue recording having paused with the adjacent Enter key.
| = Zoom to selection - handy if you have just created a selection with { and } keys.
Alt space = pause. More handy than ctrl space.
And the really handy one -
space changes focus to main window and starts or stops transport, regardless of which window you are in, unless you are typing text into a marker name dialog. Note that this will also have the same effect if you are in any other window such as notepad, however (eg it will jump out of notepad and start/stop Reaper). I may be able to improve on that soon.
[Updated just now - previous version would start recording if trackname had "n" in it - oops.]