Sweden took in more refugees than it had infrastructure to help integrate with.

To be clear, this was a choice. The amount of disinvestment since the 80s in social housing, schooling and other social programs has been truly remarkable.

100% agree. This started with Feldt's "Framtid för Sverige" which started the shift towards privatization arguing that labor costs were unsustainable. Then deregulation of investment and real-estate markets in the 90s and finally the removal of arvsskatt (2004) and förmögenhetsskatt (2007) there were enormous leaps in wealth inequality at the same time as sapping the tax coffers which had built all the social programs it was known for.

Swedes are culturally insular so when there were friction points the Swedish reaction is pull back. This leads to isolation.

This is largely bullshit in my experience - people use it as a convenient explanation for what can adequately be explained by other forces

I assume you're implying racism. There's absolutely latent racism in there as well. But even if you look like a Swede, speak swedish, but have an accent or dress in a way that stands out or break some of the other tenants of jantelagen people will steer away. People of non-european descent just have it 10x harder.

This leads to isolation. That lead to ghettos and a perfect breading ground for crime and gangs.

There's no intentional isolation on the part of immigrants as much as there's a diminishing social housing stock/social housing being sold out to slumlords.

People don't intentionally select high crime areas to live in - they are not given the option to live somewhere else.

I wasn't saying it was completely intentional, I was saying it was part of the insular nature of Swedes. If you're talking about kommun housing then I agree, that's procedural, but it does require someone who knows the process. But if you want to rent second-hand, you need to meet that person and if you're not a Swede many people will require a Swede to vouch for you.

Because of Swedens laws protecting minors the gangs have figured out that paying them for hits on rivals and their families had little penalty. This started in Denmark as their testing ground.

Using kids for gang hits is common in other places as well, because kids get more lenient sentences in other places too. See the U.S for an example on this trend being present earlier in history.

Its just new in the sense that it's the first time for Swede to have experienced it.