What about roman baths? Were they just bathing naked in front of strangers? (Admittedly less weird)

Yes! Nudity in public baths was common and casual. To the Romans, nudity was not so much an issue of morality as custom. If you’re out in public nude, you’re acting like some ANIMAL! Or worse, a barbarian! But nudity in the baths was normal - it was only custom that made public nudity unacceptable. Seeing someone nude was not in some vague sense immoral for you, or even for them. Just deeply inappropriate, like doing a handstand during a serious election speech.

Sometimes worry was raised over the issue of men and women bathing nude together - in some places and times in the Roman Empire, it was accepted - at others, sexes were segregated either by time ("1-6 for men’s bathing; 7-12 for women’s!” sort of energy), separate bathing rooms (rare because of the cost, but attested to), or separate bath-houses entirely. Non-segregated and time-segregated were the most common forms.

And i wonder how this worked when they transitioned from polytheism to Christianity… Were early christians more pro-nude bathing and shared-pooping than modern christians? Would be a shame not to make use of a nice big public bathhouse

Early Christians actually criticized public baths (and to a lesser degree, public latrines) for exactly the reasons one thinks of. It was a major debate between Early Christian thinkers, whether attending such amenities was appropriate for a Christian.

“Luckily”, with the fall of the Empire, all the complex infrastructure that was required to keep those public baths running in the former Western Empire fell apart too, and Christians no longer had to worry about such luxuries leading them astray from a life of good, wholesome asceticism and oneness with God!

The surviving Eastern Empire kept up the tradition of public bathing, but with MUCH reduced scale and emphasis.

And i wonder how this worked when they transitioned from polytheism to Christianity… Were early christians more pro-nude bathing and shared-pooping than modern christians?

Probably, it’s just a slow transition. I’m from Finland and I’ve done both, although admittedly sharing a poo is less common. But some outhouses have two holes next to each other so that you can shit in one and piss in the other (obvs not absolutely necessary for all men but) and the reason you might not want to mix them if you can avoid it so that you can empty out the pee often without having to clean the poo. anyways we were at a cottage when I was 18 and decided to have a shared morning shit with a friend of mine.

Being naked together is completely normal as long as you’re wet with sweat and completely naked. When you’re just wearing socks and have dry skin, then it starts being something sexual, weirdly enough. Most public saunas even have signs saying you’re not allowed to wear a bathing suit.