Except that by doing that the Klingons were violating their peace treaty with the Federation.
Which is meaningless to the people of Neural.
Yes, but only because the Federation forgot that the treaty was imposed by all powerful aliens who could just smite the Klingons.
Also that the Klingons were untrustworthy assholes so the federation should have included orbital death cannons as part of the treaty.
I also I wonder if the Klingons forgot what happened the last time they picked on a supposed lesser race or the fact that there are a lot of godlike being in the TOS universe before being assholes.