Bavaria was a very agricultural heavy state, that made a few things right in the last few hounded years. Bavaria has like every over German state a long and rich independent history. Only Bavarian nationalists dream of an independent Bavaria. Hitler joined the NSDAP in Munich and it was one of it's early strongholds. Most German cities were destroyed in WWII. Germany did not "pay" reparations, because they still had a lot of open dept from WWI. They paid with land, factories, infrastructure and forced labor. What the guide meant was probably the so-called "soli". It is a special tax that was levied from former Westgerman states to support former GDR states, which did not develop as much under the socialist rule. That tax was and is controversial and was changed to nowadays only applie to richer people.

Bavaria was always a big state in german, that tries to play a special role. Especially their main party the CSU participated in German politics, while enforcing predominantly Bavarian Interests. These methodes were obviously anti democratic but only borderline illegal and forced the government to restructure the parliament.

So yea. I grew up in Bavaria and I get why most Germans are quite annoyed with bavarians.

It is the German Texas.

During that tour, we learned that pretty much every stereotype Americans have for Germans (lederhosen, yodeling, beer and brats, etc.) are actually Bavarian culture, not German.

So for lederhosen, it's mostly true, although they're traditional in Austria too. Yodeling is Alpine culture and not specifically Bavarian, meaning it exists in Bavaria, in Austria and Switzerland. For beer, only weissbier is truly Bavarian; e.g. pilsener originated from Czechia, lager originated from Austria [til!]. And although there are Bavarian bratwurst variants, bratwursts are not specifically Bavarian. However, veal sausage (weisswurst) is exclusively Bavarian.

And Germans are actually quite offended at the confusion we have between their culture and Bavarian culture.

That is true. I think to some degree this confusion comes from the fact that so many Americans were stationed in Bavaria after WWII, so they only got to experience this part of German culture.

[...] when the war was over, they not only had to rebuild from scratch, but also had to contribute to rebuilding the rest of Germany, as well as paying for war damages for Europe and all Allied nations, etc. Their wealth was pretty much depleted and their hope of being an independent nation was gone.

I am not particularly versed in Bavarian history, but note that some Bavarians have developed a bit of a fetish portraying themselves as victims of injust decisions from on high. I would take that info with a grain of salt.