this exec “camera.sqs” in ArmA 3?

[] call BIS_fnc_cameraOld;

Use it the same way, WASD to move, keypad numbers to rotate / tilt, press LMB to save camera position to clipboard.txt file in profiles dir.

Cinemaborder

To turn the cinema borders OFF, do this:

[false] call BIS_fnc_cinemaBorder;

With ArmA 3 cutscenes you can simply use endmission to end them, no need to make variable which you set true and destroy camera.

endMission "END1";

Or was it this:

"end1" call BIS_fnc_endMission;