Thralldom is even more horrific than in real life. In real life, thralls could possibly be freed by their owners. In real life, thralldom doesn't affect your afterlife.
In NQ, thralldom totally does. A Norseman enthralled will never be an Einherjar, thralls aren't the honored dead. Thralldom is therefore extra suck.
To be fair this isn't quite true. We literally just had a whole big fight about it! As long as you can get free and get someone to take vengeance on you as payment for enthralling you (or, from IF's statement, just get them to pay weregild to the wronged party) it cleanses the shame of Thralldom. This would presumably cleanses the spiritual shame as well, and allow them to earn their place amongst the honored dead (or not).
Church Gold
Is there any value in a church holding gold and silver? Is there a cultivation advantage to be gained? Gold and silver are basically Norseman bait as they fall over themselves to loot your wealth for Orthstirr.
What was the use of gold and silver in real life? Appearing rich, paying bribes, and all things similar. Gold was literally a worthless metal for much of the world, with no use besides Shiny. And yet people hoarded it. Churches extracted it from their worshippers as much as possible. Kings made it rhe basis of their riches.
Something doesn't have to be useful to be valued. See; diamonds.
Raids
In real life, the concept of a raid is that you hit people who are not ready. Quick strikes before an army can be raised to respond to an attack. Note the key word here. Army. In NQ, raiding other Norse people gets you face full of veteran Norsemen because all Norsemen can fight. Unlike real life where actually a lot of Norsemen probably don't fight that well. In real life, raiding Carolingan lands before armies can be raised to chase you off is plenty viable. In NQ Knights can be active basically 24/7, raising the question of raiding viability.
How do raids work then? I dunno, but it's definitely harder than IRL by a whole lot.
Raiding was still a dangerous and deadly activity even irl with that mentality (which is also not completely correct). There are hundreds of gravesites we know belonged to Viking raiders just across the British isles. There's more elsewhere. People died on these raids, even when striking those who are unaware and unprepared. Battle is, in general, a lot more deadly irl.
And raiders happily engaged with fortified positions with archers and shit at times, which are far from 'sudden ambush against rhe unprepared'. They generally would do their best at tilting things their way, but this wasn't some 'they only struck undefended fishing villages'. They knocked over actually strong positions to get the tasty gold goodies too. And this is a world where a single arrow from a single 'mortal' guardsman could/would get infected and kill your ass.
If anything, foreign raiding is much safer in Norsequest than irl, because only one in ten (a hundred? A thousand?) Men is going to be able to even harm you. Everyone else is a joke. And even if your arm gets cleaved off, you put some spit on it and finish the fight and then heal it later. A smart raid can spend time Scouting and figure out where knights are and avoid them, because Knights are the one real threat. (Priests seem a lot less threatening)
Raiding other Norsemen is no more of a threat than irl either; its actually literally the same. Every norseman exists in the same paradigm, whether that's RL (all men learn to fight, no magic) or NQ (all men learn to fight, magic). The only difference is the same difference between 'are you good at fighting' and 'do you suck at fighting', though yeah in NQ that scales larger.
Culture and Atrocities
In real life, sacking/burning/ruining a sacred place, where be it a sacred tree or temple or mosque or such is generally agreed to be a bad thing. Ruining places of great cultural or religious value is not good, should not do.
In NQ, culture is cultivation. Places of great cultural value are places of cultivation value.
This means they have military value. This makes them targets because of their great cultural value.
Conclusion: RIP culturally important places.
I mean, that's all from a modern perspective. The Norse IRL loved hitting monasteries and burning them down for the goodies inside. It wasn't because of military value but monetary. I don't think that needs to change here; what's changed here is that monasteries are probably scary and strong places. Multiple priests. I'd expect monks to have some level of cultivation too, Nuns as well. Or at least cultivation-like tricks they can pull since they're Holy.
Burning shit down because you're angry and you know it's important to the people you're angry at was the norm for much of the world though. The crusades happily destroyed every mosque and artifact it came across. The wars in Spain (both Muslim conquest and reconquista) literally targeted places of worship as major targets to destroy the cultural value. Hell, the christianization of Ireland destroyed so many cultural artifacts that we barely have records of what predated it. Let alone the Norse.
RL firmly believed in demoralizing and weakening people by destroying their culture, and showing they're weak, while showing that their own culture is strong/favored by whatever god. The crusaders shouted how God was on their side as they burned mosques as proof of how Islam's God was not real. The same was done by Muslims in wars with Christians! The same was done by basically every religious conflict.
All NQ does is make what people already did in reality have military value, as well as the perceived cultural value. Burning that mosque is probably gonna legit harm the cultivation ability of the Imam until its restored.