The action taken by Mubarak against the Palestinians is the single most important reason for the growing resentment.
Well, no. The Palestinian thing was not an issue at all. You predicted wrongly.
You are also wrong about the protests being against American-backed dictators. It just turned out that American-backed dictator leave office comparatively peacefully. Gaddafi is for all intents and purposes a dictator backed by Cuba and Venezuela (and all three dictators were backed by the Arab League).
You also overestimate the love other Arabs have for Palestinians. In reality they don't care about them. They treat Palestinians like scum. It's the west that gives them money and cries for them, not the Arabs. Arab countries regularly keep Palestinian in concentration camps, throw them out of the country or revoke their citizenship, even in Palestine (i.e. Transjordan). The Arab public has never protested because of that.
The revolts were about freedom and nothing else. They were not about "Palestine" or about the US except in as much as the most prominent leader of the Egyptian revolution is a Google employee and that the Egyptian middle-class that led the revolt is American-educated.
Mubarak has also done nothing "against the Palestinians" (who are represented by the PLO) but against Hamas. Hamas is not very popular in Egypt.
According to the latest polls, less than 20% of Egyptians support the Muslim Brotherhood and Hamas while 37% support the peace treaty with Israel (22% oppose it). Those 37% for the peace treaty are likely a higher percentage than you would find among western non-antisemitic peace activists which is one reason why I prefer Egyptians (and all Arabs) over western "pacifists".