> These three countries’ job market is accessible with a Schengen visa.

Is that true? I'd have assumed that EU citizens have access, but non-EU would need to apply specifically for FL/CH work permits.

(and I'm not sure, is there actually a EU-wide work permit for non-EU? I had the impression that each country is still handling non-EU permit separately)

(tourist visa are different of course)

I don’t know about FL but for CH you do have to apply for a permit. However, if you have a job offer and an EU passport you basically just pay the fee for the permit and you’ll get it (usually for five years). And af r the five years you can either renew your work permit or apply for permanent residency.

Same goes for CH nationals who want to work in the EU.

Definitely as CH takes part in the freedom of movement with EU.

My comment was really about non EU+ nationals. If you get a working permit as a 3rd party national with no treaty with EU, in eg Germany, can you just move to Spain and work?

I think so, yes. At least that’s how I understand residence works: you get a residence permit for say Belgium and you can use that permit to move and go live in Portugal for instance. Not an expert and no first hand experience with this, I might be completely wrong.