Is there a shortcut key or menu option to quickly collapse all code? I only want to see the function definitions.
Yes (more or less), "Fold to level".
I am not sure if a (or which) key is assigned. You need to check that in: Tools > Options > Editor > Keymap: (search for "level")
Then you need to find the "level" for the procedures.
E.g. if your fold config includes "unit section" then procedures may be the 2nd level, otherwise they may be the first level (nothing that will fold outside them).
Of course, if you have "class" fold too, then they may also fold at that level.