Throwing a tantrum about school supplies is petty. Sending everything in with your kid's name on it when you're not supposed to does not help anyone, especially not your kid. Accusing your child's teacher of stealing crayons and tissues is just plain idiotic. Do you really want your child's teacher to think of you as 'that mom'? Do you really want your kid to be teased for having his own personal, labelled supplies while everyone else uses the communal supplies? Kids will tease anyone about anything all day long.
And don't forgot, teachers talk to each other. If you're a complainer, people will know. You only end up hurting your child when you throw a fit about stupid stuff that doesn't matter.