NJ, what you say about Greece etc. lacking self restraint in taking loans is akin to expressing of concern over alcohol being available to alcoholics. Is the responsibility that of the producers and should we do away with alcohol (loans) altogether (close down the euro) or do we allow it ? Bootleg booze (overspending) will still be around. Not the best of comparisons but you'll see what I mean. The loans were available for development, external oversight/vetting may not have been adequate but that is not the fault of the currency per se.
Unlike the UK, Sweden has a very straight forward national management system whereby of those who are legally in the country they basically know exactly who everyone is, where they are and an up-to-date list of everything. It is more or less true to say nobody can legally exist in the country, take part in economic activity, obtain state assistance, use the banks, etc. unless they are registered. This is true even of non-residents. Those who are there illegally cannot access anything unless expressly sanctioned by the system which then registers them so they become trackable "faces".
The dilemma for the Swedes, like Germany, France, etc. and also the UK (without the benefit of a robust admin/management system), is whether to expel people, many of whom are in a bad situation, and then where to. All these countries have largely held back, although expulsions do take place. The authorities in Sweden are as responsive as anywhere to the concerns of their citizens and they are apparently not preparing for any drastic action in Malmo. They are still trying to find out who killed Olof Palme by point blank gunshot long before Sweden entered Schengen and years before Sweden joined the EU.
At one point when the congregating of would-be UK immigrants in and around Calais caused friction between the UK and France, a French minister (can't recall which/who) said in some despair that "if only the British had a system" things would be easier to deal with. France sees things differently from Britain. It is not at all difficult to persuade people to become worried. According to my knowledge of Swedish issues (which admittedly is limited), they are aware that they are being tested by the pressures but so far they seem to be calmly adjusting to a new reality, whether temporary or permanent. They too have different types of extremist elements among them. They too feel the consequences of the fallout from the West's past mistakes and misdeeds on the world stage and home grown reactionaries.
It is geography that has put Italy and Greece under particularly great pressure but other countries feel it too. There have been temporary border arrangements but so far no serious call for abandoning Schengen has emerged. The reason is, just like on the island of Ireland, free movement (physical and economical) is very highly valued indeed - only the blinkered knee-jerkers genuinely fail to appreciate that.