Getting Slapped Isnt Nothing.
Is it legal to slap someone. In the case of punching someone its likely to be classified as either simple battery which is a misdemeanour or aggravated battery which is a felony crime. You cannot push the person simply because you are annoyed or pissed off. You do not have the legal right to punch someone just because you are pushed.
A slap is used exclusively on the head and neck and is lethal force. Punching someone is assault and that is certainly illegal everywhere in the world. Most people would back off and not resort to trying to get you arrested for assault but it certainly isnt legal.
You are well within your rights to sue someone if they punched you. An injury which could require a doctors attention and therefore cost money. Ive known officers that carried them back pocket and never thought it was a good idea but they were old school and had been doing it for decades.
The law has long recognized specific limitations when it comes to speech such as prohibitions against slander and libel. Slapping someone on the ass isnt anywhere near breaking someones nose. So no neither things you said are legal but if you do punch someone if they punch first that may or may not be self-defense which is basically an excuse under law.
A slap could be criminal Harassment Although a slap may not always constitute an assault under the criminal statutes there are other charges that could be brought. However self defense is a defense to an assault charge. It is absolutely NOT legal to slap someone for the simple offense of not leaving you alone.
In fact according to Colorado law where I am from it is perfectly legal to spank as long as no marking or bruise is left. This is an interesting point of view however most state laws are quite clear on whether or not physical punishment is defined as abuse. Punching someone is assault and that is certainly illegal everywhere in the world.