socialism is a political system that demands a particular economic system - a planned economy. A planned economy in itself is not political, in that it's a specific way of organising labour. A barter or gift economy are also economic models, neither of which are inherently tied to a political system.
"Socialist" as a slur for Obama was in reference to the political act of taxation and wealth redistribution. Neither of these things are capitalist, and the term "socialist" has a somewhat different meaning to the original political system, when it comes to American politics. American "socialism" is more akin to social democracy i.e. a capitalism-driven welfare state. At least, that's my understanding.
McCarthyism was political, nothing to do with economics. The CIA interfered with other countries' political process (i.e. staging a coup).
The whole idea of capitalism is that people join together in free association to trade for mutual benefit. The responsibility ends there. If I buy your goods and then somewhere down the line you decide to use that cash to buy a weapon and kill someone, I am in no way responsible for that because it is a separate transaction that I did not enter into. Ergo, trading with Thiel is not a political act that can somehow be ratified retrospectively. It is an economic act. If your agreement was "I'll trade with you on the condition that you donate the profits to Trump", then it becomes political. From my perspective, the distinction is pretty clear to be honest.