And rights have to be expanded continuously to prevent the slippery slope?
No...
If a single person feels disenfranchised then the whole edifice slips down to tyranny? Of course, that is absurd.
No...
but we have problem about the word
"rights" itself ., what rights are we talking about? let us take examples from your own statement
1). Close religious schools,
2_. stop foreign funding,
3). ban face coverings
4). and leave no doubt that a state within a state will be (NOT) tolerated.
those are the points that are from your post that you think a government of a democratic state should control with force ,.. now compare the rights in those 4 points with universally recognized Human Rights, such as
Right to self-determination
Right to liberty
Right to due process of law
Right to freedom of movement
Right to privacy
Right to freedom of thought
Right to freedom of religion
Right to freedom of expression
Right to peaceful assembly
Right to freedom of association
and figure out those four points whether they are trespassing the above fundamental rights .. along with golden rule ..debate .. discuss with those who are opposing your views and convince them that you are right ..
that is all what you need to do

I agree it is a tough problem but I think Human beings are intelligent enough to participate in such open discussion in this 21st century