I see some contradictory statements here, perhaps you could clarify those for me.
You believe the Democrats to be unwilling to improve on social matters, be it both domestic and foreign, correct? They may state that they hold these beliefs, but you don't expect them to make a meaningful change, which is why you don't see a path to improvement under Harris. I hope I understood you correctly here.
At the same time however, you seem to believe that electing Trump will lead to a civil war. Who exactly do you expect to start said civil war here? It won't be Trump as he's already in power, and it won't be the Democrats either because they don't genuinely believe in liberty/democracy. If they won't even vote for it, how can you expect them to fight for it? I'd argue electing Trump reduces the chance of a civil war, even according to your own logic. And even if a group other than the Democrats were to take up arms, that group would certainly be smaller than a Trump-led government backed by the US army. Trump would win in that case, and any hopes of progress would be dashed completely.
Any side with a shot at winning a civil war would have to be either the Democrats or the Republicans. Since the Democrats wouldn't start a civil war (too spineless), the Republicans have to. And I'd posit to you that the only way they would do so is if Trump loses the election and contests it, riling up his base. We know that his base is radical enough for it (see Jan 6), and Trump is too much of a narcissist to refuse the chance. In this scenario, Biden/Harris would have to use the army to put down the insurrection, and the political momentum from that might give people a shot at improving things in the way you want. Arguably there's historical precedent for this, with Lincoln having the momentum to ban slavery during the civil war.
You also seem to, and I quote "believe in the American people". But that same people makes up the US army, makes up and and supports both political parties and also seems entirely complacent to keep voting for the same two sets of douchebags and not push for electoral reform in any meaningful way. In fact, you don't even seem to think that the Democrats could be pressured into change, not even on the matter of Palestine. Either the Democrats are unwilling to change a position in exchange for power, or said pressure isn't as big as you seem to think it is, and most Americans just don't care enough (which would also put a pretty big dent in the whole "civil war"-plan.
Frankly, it seems to me that the accelerationist civil war strategy makes more sense when you elect Harris. But I'm not sure if it's worth pursuing at all, since I can't think of any historical precedent where this has worked out.
Silly Americans, submarines are supposed to sink! This was clearly a successful test.