Yeah Tony was a terrible boss, the only one i disagree with is it wasn't just over a horse Ralph was killed that was the last straw. Killing that stripper at the bing and pissing NY off with that Ginny Sack joke were punsihable by death as you put it imo. Also him being just a genuine hothead, who could've flipped at any moment. The rest i completely agree with though.
Ralphie killing that horse IMO was some sort of revenge against Tony who took his girlfriend Valentina. Remember how Tony beat the shit out of that senator for dating his ex-mistress but when he himself started dating Ralphie's ex he expected Ralph to just accept it and move on. Another example of him being a bad boss.
