Well yes, if the US were one of those parties then it wouldn’t be a “proxy” war. Assisting one side without being directly involved is the definition of a proxy war. Proxy wars aren’t necessarily aggressive or wrong, either.

No, the US's response has significantly changed since the start of the Russian invasion of Ukraine to the point where regime change looks like it's in the cards. There are very clear corporate and regulatory interests in a Russian regime that complies with western governments. If lobbying efforts can cause site blocking in trade agreements, why wouldn't that be the case for regime change negotiations?