There is no 'paranoia' about migration, rather a reasonable response to a calamity.
In 2015 - entire nations population swelled by double digits as irregular migrants swept through - for example, Hungary, Austria, Bulgaria etc. are only the size of a small American city.
So, can you imagine if 3 million migrants swept through Sand Diego? Or 30 million migrants swept through the Southern US? Would this be 'an issue of concern'? Of course it would - and that's the relative magnitude of disruption for some of these countries, particularly the tiny Balkan states which are quite poor - so much so that citizens of places like Albania are just as poor as the migrants sweeping through there.
In 2017, the migration issue is no longer Syrian, as the aggregate numbers have calmed, but there are still a considerable number of migrants arriving, mostly from Africa, via Italy. [1]
As for their 'qualification as refugees' - it's generally true that most don't qualify. It's hard to quantify precisely, but merely being from an African country does not immediately qualify one for status. Migrants from Eritrea (Africa), Afghanistan and Syria have special status and are generally processed differently, but again these groups (at least the later) are not so common.
And of course Schengen definitely allows for countries to put up border controls on an as needed basis, and the current migration calamity is a reasonable candidate for that need.
Just as some people are too ideological about hard borders, we shouldn't be so ideological about open borders either; 'Smart borders' ie more open where they make sense, but with practical flexibility I think are best suited.
As for Germany/Belgium and similar enclaves ... it only works when there is an economic and cultural equilibrium between nations - otherwise, it's just going to cause problems. A tiny hole in a border can create an existential challenge for nations, and massive humanitarian and legal headaches.
I should add that border checks go up and down for all sorts of reason, and this is not a new thing. I know that in the early 2000's I was stopped a long between France and Italy. I don't know what the issue then was, but it's not like it felt odd to have to waive to the Gendarmes while crossing an international border.
It's a big issue with existential and permanent consequences, so it has to be taken very seriously, with deliberation.
[1] https://www.swissinfo.ch/eng/politics/italy-swamped_switzerl...