I agree with everything you say. Afghanistan and Iraq would be a mess. Ukraine would be in an underground guerilla war. Poland would have it's army at the border with Ukraine. Trump would be buddy buddy with North Korea. China might have invaded Tawain already. The big international issue would be how far Trump would push into Mexico. I have a feeling he would've probably sent troops into the border regions in Mexico and maybe central America to protect the border or some nonsense. Domestically things would be a mess as the MAGA crowd feels like they can control the narrative. You are right though, the Senate and Congress would be in Democrat hands as people would be very pissed off still.
But, I disagree that all he would've done is make noise. He is much more dangerous . The big question is who knows what diabolical crap that Stephen Miller and Steve Bannon would come up with to try to keep Trump in the White House. Just like they are plotting now to install their stooges in all levels of the federal government when they take over again (if they take over).
The big question is what would Trump be doing now. I doubt he would just roll over and walk away from being president...