Dual nationals can be denied a security clearance if there are concerns about their loyalty.
Quite irrelevant, given that the vast majority of us have no need to hold any sort of security clearance. My interests are in education and IT, neither of which requires a security clearance or will ever require one.
Ordinary working people don't support PO.
Obviously your knowledge about the Polish electoral system is missing along with everything else. Poland has a system of territorial self government, which is responsible for a wide range of tasks from tax collection to administration of education. PO control 8 provinces, and with it, control a significant amount of tax revenue as the PiS provinces are poorer and rely on fiscal transfers from the wealthier provinces.
The Germans and the Austrians want to destabilize the democratically elected Polish government, and subversives in the country are working to help them.
Sorry, but they were organised by Poles, just like the demonstrations in the UK, USA, Canada, Japan and elsewhere.