emoji is a good sign of human interaction with the others in a way will not make others feel teased or upset.
when i am angry i post happy emoji this will release me from the pressure sometimes
and for your second question, yes it must be limited, so it will not be boring.

however, i will upvote my comment due to silly point , this donkey @cheetah is downvotin all of my posts and comments so to overcome the ngative value deducted from my reputation, i upvote my comments - silly ha,,!!

I have upvoted this post and resteemed it too

good work my friend

thank you