To begin (& something I probably should have said at the outset...

), I'm adopting the pre-Munich idea because it brings Hitler closer to his dream, attacking the Soviets.
It's less than a year in difference, and as others too have pointed out, doing Munich first before going after Poland much betters the strategic (and economic) position of Germany. A confrontation with Poland, much less the Soviets is much safer if Czechoslovakia is neutralized. IMO it makes no difference in the long term (since the Wehrmacht needs a couple years buildup for Barbarossa anyway), so the difference pales, but post-Munich is much safer. I understand the urge to be orginal, but the pre-Munich scenario does not compute as good as the post-Munich one.
I incline to Japan in SEA, but without war in Europe, maybe not. Finland or Romania might be more credible. Or maybe your scenario below obviates the need for annexation by force in favor of satellitization.
Possibly. It depends on whether Stalin is pushed to caution or preemptive expansionism by British-German detente. As for annexation/satellitization, as long as the leadership of rump Czechia is willing to cooperate with Berlin, annexation is not really necessary, or may be postponed (since as a matter of fact, the economic benefits of annexations exists) till the right oppoirtunity. The Czech leadership was fairly cooperative with Germany after Munich, so a wiser Hitler has reason to wait for annexation.
That's an excellent question. I picture combined pressure from the 3 plus the implied threat of attack from Russia.
Indeed that would be the scenario at Munich II. It remains to be seen whether the Polish leadership would be rational enough to choose a cutting down of the country to its core rather than a combined German-Soviet invasion with no hope of help. IMO they would probably accept, but the interwar Polish leadership rivaled the Japanese generals in megalomanic nationalist stubborness, so it's not a safe thing.
He might, in a moment of lucidity, offer Poland a variety of the Russo-German Non-Aggression Pact, with a view to gaining Polish co-operation (if not active aid) in attacking the SU later.
He offered such IOTL, but they refused, because they could let go of their inexplicable fixation that loss of Danzig meant the end of Polish independence. Here they would not have any hope of Anglo-French help, and a two-front war on the horizon, so things would be different.
That reaction I'd count on. And I'd bet pretty heavily Hitler would tell the Poles to expect it, & that they'd be pretty sure they could.
Agreed, again. It's a toss-up, IMO, which result obtains: satellite or partition. I don't feature Hitler being too compliant to Stalin, but if he's smarter TTL, & aware (enough) of Wehrmacht weakness, he might be willing to delay.
It can safely assumed that he would, since IOTL he waited between 1940 and 1941 the necessary time to prepare Barbarossa, and here we are assuming ihe's smarter.
I've seen that thread (I think, or one very like it). Given Hitler's a bit smarter TTL, that's the way I see it going: Britain neutral/mildly anti-Soviet. I think both Hitler & Stalin would have to wait some small while (6mo? 1yr?) to get weaps production in gear enough, to mobilize manpower, so on. It's possible TTL would see "Barbarossa" with Pz2s & 3s facing BT-7s or T-26s, 109s against I-15s... I'm not sufficiently informed on the dates of introduction of Pz4, MiG-3, LaGG, T-34, & so on, to guess.
Gotta ask someone else for that, my expertise is on politics, not the military. But IMO 1-2 years is the absolute minimum necessary. Any earlier, and it means that Stalin forced the issue by invading Romania. Germany would answer with war to any Soviet threat to the Ploesti oilfields. Most likely even if the British are friendly and there is no threat of blockade.
Your proposed outcome is very like the one I envisioned. Glad to see I wasn't on Mars.
Great minds think alike.

It's just possible it's sparked off by Nomonhan (OTL '39), under the Anti-Comintern Pact (or is it signed OTL yet?)...
It was signed, but it was far, far, far from being a full alliance committment, more like a vague statement of a common agenda. You may mean the Tripartite Pact, but that was signed in 1940.
It is possible that Nomonhan may blossom to a full-fledged war, if the Japanese are more stubborn than OTL and seek a rematch, but IMO it is unlikely that Hitler would rush in a war with Stalin before he's half prepared, just because the Japanese are fighting on the side of the globe, the drawbacks from incomplete preparation outweight the benefits.
You may see a Russo-German war happen before its schedule, but you need a sparking point in Europe. Possibilities: the Winter War escalates, either the Swedes intervene and Finland collapses and Sweden itself is threatened with invasion (if Sweden iron is threatened, Hitler shall be forced to war), or the British choose intevention in the Winter War (if given the possibility of a British alliance, which Hitler coveted, he would accept a war before he's ready), or the Romanians choose to fight for Bessarabia and they collapse in the ensuing war (same reasons as Sweden, Hitler cannot accept the loss of the oilfields), if they hold out like the Finns it's possible that the Germans just send a lot of supplies and "volunteers", or again the British choose to help the Romanians.
That being so, no Pacific War.
Yup, not unless the Anglo-French look too distracted elsewhere (such as figthing a war with the USSR

).
Possibly U.S. aid to both sides,

or at least no interference with aid to ROC.
Aid to Japan if they fight the Soviets ? Possible with another POTUS, not the Commie-loving Roosevelt.
I'd love to see Chiang cut a deal with Japan (he'd have done it to get peace so he could destroy Mao/CCP) & join the war against the SU, but maybe that's a bit ASB.
IF Chiang is willing to let the JP have Manchuria, and the war is faring badly for Japan, he might cut a deal with Japan to get them off his back and go back wiping the CCP. Of course, Stalin might well make an offer of their own to Chiang, and order the CCP to disappear in the woodwork (they might or might not obey). He might or might not offer Manchuria to Chiang in the peace deal. It's a toss up which side Chiang might choose, he has little claims vs. the Soviets either way.