These are our basic rules in Western democracies.
...
In democracy there is not any exam or authoritative institution that can stop someone to preach Christianity, Buddhism or Islam as he likes. In the respect of law, of course. You can join your friends in your living room and preach the gospel of the Spaghetti Monster or the Saints of the Ninth Day if you wants.
Since we are trying to learn lessons here, here comes a pretty difficult lessons or problem for which i do not know an answer or solution:
As you say in the rules of "Western democracies" the concept of some intrusive oversight of what is preached is nearly or completely alien.
These rules were developed in societies with certain religions having a relevant role in society. And they worked and continue to work today. With said certain religions and also with some other religions.
The unspoken, never considered, never realy discussed assumption underlying this:
That religious freedom which worked fine with said certain religions having a relevant role in society, WILL work just as fine with ANY OTHER of the thousands of other religions having a relevant role in society (to clarify, not several thousand other religions have relevant roles in societies; the assumption is that if suddenly a 100 million converted to wiccan religions in Japan, making wiccan religion suddenly relevant in Japan, it would not be any relevant issue for Japanese state).
This assumption seems true beyond any doubt as long as one considers the content/teaching of the religions to be irrelevant. But that is also just an assumption.
And here what that representative from a theocratic-totalitarian monarchy says is relevant:
An Arab Minister, that comes from a theocratic-totalitarian monarchy doesn’t know what democracy is, but I have supposed that you are not a fan of the Arab monarchy.
Because he effectively claims that the above assumptions are wrong (in regard to Islam or at least some important denomination thereof; but at first it is realy irrelevant in regard to which of the thousands of religions the assumptions are wrong; a single one already would be a problem for the assumption underlying religious freedom).
Can i prove that the assumptions are wrong? No.
Can i prove them to be true? No.
Are there some events that call the assumption into question? Sorry, yes. For example in the above article about that Arab minister it is mentioned "the DoC [Office for the Protection of the Constitution of Germany] monitors dozens of mosques". They do not monitor dozens of churches; not dozens of synagogues; not dozens of buddhist learning centers; not dozens of any hindu meeting places (if they have any; which nobody cares about).
And if that basic assumption is wrong, we are screwed. Cause then societies will be between a rock (violating religious freedom) and a hard place (suffering the effects of the presence of a religion not compatible with religious freedom).
I am not aware about any solution or even any approach to verify/disprove the assumption.