Bo, I think you have good thoughts but in time will use them to defend the two party system. I think you need further reading and understanding, but also more time to observe how the political system in the US functions. No doubt I do as well but I have at least a few years on you.
I could put forward an argument that the two party system is the perfect vehicle for mass democracy. On the one hand, it is a check against the monopolization of government by one party, which I am sure we agree is a positive feature of two parties over one. But there is a case to be made that the two parties are better than three ore more. You could describe the multiplicity of parties as ideological fragmentation - competition between the parties would be more about the competing ideologies rather than an up-or-down vote on the party in power. Above all, the two-party competition is a yes / no on the policies of government. One party will always be the in-party, the party of government, and the other party the challenger responding to the actions of government, and their consequences. (A by-product of this is that both parties generally will support a core set of centrist policies). So, the two party system avoids the danger of a one party state by having meaningful competition, but not so much competition that the focus shifts from the success / failure of government to partisan ideologies.
But this is just thinking out loud - I think the better argument is that the United States has been stable and successful for a very long time with a two party system, yet has certainly experimented with many different philosophies and agendas. Proof is in the pudding as it were.
I think it is worthwhile to separate policy from politics, for the purposes of evaluating the two party system. America self-evidently features a very long streak of good policymaking. That is true even today as ours is the leading advanced economy in terms of growth. That said, I do think that the two parties degrade political rhetoric and the public discourse, and arguably moreso than either a one party or a multiparty state. The attack style of politics is something uniquely realized in a two party system. *But* on the other hand, both out party and in party have to constantly shift their rhetoric to be responsive to the demands of the electorate, which are ever changing, sometimes predictable, sometimes participatory / emergent, and sometimes seemingly random. The point is, in a two party system there is a very delicate balancing act which is ultimately focused on the desires of the electorate in very subtle ways. That is why US politicians can say things which are very generic sounding but communicate both very little, and very much, at the same time. There are layers and layers of mass psychology and implicature and idealism and practicalities embedded in US political rhetoric.
Contrast this in particular to a likely outcome in a multiparty system. Without the constant competition between two forces, each about as likely as the other to gain the upper hand, parties will primarily have conversations with themselves about their ideology and rhetoric.
Finally, there's something aesthetically pleasing about a two party system, in a dialectical, dualistic way.