Ok, i don't know those maps, and i've never tried the camera angle mode before, but i can help you with the start.
Make a nontarget dummy ability without manacost and add 1 sec cooldown(to avoid bugs)
I would recommend Berserk, since it's almost instant and won't change your unit's actions if you want it to be changeable in-game.
Events - a unit starts the effect of an abilit
Conditions - Ability being cast equal to (Change Camera Angle)
Actions - if/then/else(multiple actions) (boolean variable) is equal to true
Then - set (boolean variable) equal to false
(Put camera triggers here)
Else - set (boolean variable) equal to true
(Put camera triggers here)
U'll need to make the variable an array and add the players numbers there(player number of (owner of (triggering unit))) to make it MPI
Also i believe there is a camera tutorial on this site or maybe at wc3campaigns.net or theHelper.net