The Nord Stream 2 sanction regime was always going to fail, because it wanted to impose costs on Germany especailly to further an exclusively US foreign policy goal (note, I don't count Baltics and Poland getting a chub at Russia being discomfited as an actual foreign policy goal). Merkel has never been supportive of Ukraine in the same way that the US has, and reiterated during Maidan and since that the politicians saying Ukraine would join the EU as a matter of course were lying. She's also a lot more realistic about exactly what Ukraine's behaviour entailed than the US- like Yulia Timoshenko going from owning a VHS rental store to multi billionaire in a few years when she got her hands on the gas concession. The blatant theft and graft of Ukrainian leaders wasn't just costing itself or Russia, it cost down stream partners as well who ultimately had to pay for the gas filched.
Hilarious though thinking about the US reps who actually thought Europe would opt for massively overpriced imported US gas, despite there being no infrastructure at all for it and it being, well, ludicrously expensive. Biden is just accepting that the US played its cards and lost, world would be a lot better if countries behaved that way more often and didn't dig in just for the principal of it.
Qatar got too big for its boots. Its citizen population is minute, but it's very rich. MbS was by most accounts planning on a literal invasion and annexation, not just sanctions and a blockade. Stopped by Turkey mostly, but also because the US would not approve it due to having an absolutely massive base there (which quite apart from the negative appearance of allowing an invasion would have to go as there was no US basing allowed in Saudi)
Pretty much anything about MbS can be explained as him being the ultimate trust fund baby- never had any consequences for his mistakes previous, so had a massively inflated sense of his won competence and no idea of how others would react when they weren't directly beholden to him. See also: Yemen and the break up of the alliance with the UAE, and somehow managing to run Saudi Arabia's economy at a persistent deficit.
Hamas is basically Ikhwan (Brotherhood), which is Sunni. Iran is Shia. The main Ikhwan backers are Turkey and Qatar, both of which were vehemently opposed to Assad. So Hamas betrayed Assad and Iran and sided with the Syrian rebels which had a sizeable Ikhwan component (indeed the last major uprising in Syria previous was Ikhwan), while other Palestinian groups didn't, indeed one of the more effective pro government groups was Liwa Al Quds, a palestinian formation. To this day Hamas has zero presence in Syria as a result. So far as I am aware the last time any comment was made about rapprochement it was dismissed extremely undiplomatically by the Syrians.
Doesn't stop Iran selling weapons to Hamas though, and they maintain supplies to some of the smaller non Hamas groups too.
They're Sunni Muslims who believe in Political Islam. By most measures they're more moderate than the typical salafi supported by Saudi or the west, not that that's saying much, but Political Islam is a threat to most of the monarchies and dictatorships of the region, so it's suppressed due to 'terrorism'. Their aim is the same as any other party really, to attain power. They're not particularly concerned about how to do it, but then in that region no one really is. Theoretically they kind of support democracy, but only the sort of democracy that could be relied upon to elect the 'right' person all the time.