I thought it was intentional:
If you put the riptide trident in your offhand and put a fire aspect sword on your main hand and kill a mob by holding and releading right click, the mob will be "cooked" with the fire aspect sword even though you didnt left click with it.
So it's like you're using the sword along with the trident.
I might be wrong though
I cannot reproduce this
This is used to reduce lag
I think it is because of the long grass obstructing it.
Can you send a screenshot?
What you have described does not happen for me
Part of the blazes' AI is that they do not fly unless a player is nearby. If blazes fall off these edges, they would explore away from a nether fortress or get stuck in places.
This leads me to believe that this is intentional