Without a doubt America is an oligarchy. The majority of elections are won by the candidate with the largest financial backing. Lobbyist group essentially buy political capital as if it is a tangible good.
When you ask about perception Im not quite sure if you mean the perception of the elites of other countries that we democratize or of the common citizens. Democracy is primarily forced by the US. Considering the fact that a decent majority of our own citizens aren't keenly aware of how our political system works I doubt that most foreigners are aware of gerrymandering and Super Pacs. Democracy is only an ideology in America not a practice.
You made huge points here.