yes.
1
if you specifically want a end-of-animation callback you don't need a Spine Event. you can use AnimationState.OnComplete or OnEnd and register to those.
If you want to programatically add an event to the end of an Spine Animation, yea you can do that too - all be it a bit trickier, but not that bad.
2
Yes. hell you can even do it in the inspector.