The point is no rabbi goes with sandals with no socks & dressed like a slob not even the dati leumi/modern orthodox ones & the rabbis should be our guides how to act & dress properly in shul!!!! I am not saying wear a suit,kapota or bekesher but at least wear a nice clean & unwrinkled shirt tucked into your pants & shoes with socks like all of today's rabbis do without exception!!! If one wouldn't go to one's own chupa like that or to a VIP dressed like that how much more so on Shabbos & yom tovin in Hashem's presence? Why does a chupa or VIP deserve more kavod than Hashem does?
The only reason I wear clothes is religious mandate. Even then, the vast majority of the time it's shorts/tshirt. On shabbos/yom tov, yeah I wear only fresh clean stuff. I really like the golden kaftan thing Sephardim wear, looks a lot less hot than what they make you wear in Chabad yeshiva, I'd do that.
That was all beating around the bush. Yeah I agree with you, not that I have a choice in the matter, we learn from Esav who would wear his best clothes for his father that we need to look good to honor our father. On shabbos yes, it is halacha to wear the best of what you own. A segula that R. Nachman of Breslev said is that if you keep seperate shoes that are better than your regular shoes only for shabbos, it's a segula for something good I forget, it's in his Book of Segulot.
As for socks and sandals, everyone knows only losers wear socks and sandals, and I don't see the slightest halachic issue with wearing sandals, especially if they're clean, unless the smell of your feet distracts fellow daveners.
Your last point reminds me of something Rabbi Mizrachi said, "If Trump says he hates you on T.V., you feel a bit bad, so how much more should you feel shame if the Creator of the universe says he hates a type of person and you become that?".
But yeah the kapota isn't happening. I've never actually ironed a shirt either. I actually only bought two pairs of jeans and a pair of shoes in my life as far as clothes go, everyone just gives me theirs or buys me some to curtail favor. I would honestly have 0 dress code if I were ever to have a wedding, I hate those stuffy clothes they make guys wear, I like loose and free and comfortable. How do you experience creative thought or win fights when you're all sticky and itchy in them. And even those stupid $5,000 suits that look the same as every other suit, they can have silk in the middle and the edges are that same itchy material. I would have everyone in shorts and t-shirt. Or better get married on the beach and everyone can have swimming stuff. Mechitzah in the water and everything.
In business, if your tie is slightly to the left or the right, there are very self-happy people who think what they do is reading people, and I can see right away they judge you as a bad business partner for the slightest fashion crime. That's the only time I'll wear the stupid 1800s fashion everyone decided is proper. And I have women there to tell me what to wear because of the colors matching the other colors in a way girls care about.
It was a question to me, what does Hashem benefit from my skin in 1800s fashion? The answer is that obvious when you understand you don't wear what's classy in Yemen when you go to Russia. He doesn't care, it's just that many people judge people as human beings based on the clothes they wear, and they also consider wearing nice clothes to see someone as honoring them for some reason, and therefore wearing clothes that the majority of people around you think is nice makes them see you honoring Hashem and think you are a good person, and therefore they might want to honor Hashem too and judge His Torah favorably. If it was just me and Hashem though, I don't wear shoes at all the majority of the week, unless I'm going to fight someone I want to hurt alot, so I'd be not wearing much.
If you want to go to shabbos though, we learn in Gemarra that some Rabbi I forgot would wear black all week so as to make a difference with his bright, regal clothing on shabbos. Wearing black all week and wearing black on shabbos seems to violate this stringency.