I’ve never seen any numbers on how many Christians and Jews hang around to pay the jizya after a muslim conquest, but I would bet that most would flee or die fighting.
I think not. Most people don’t flee their homes or die fighting when their country is conquered. Spain was majority Christian and had a large Jewish population all during the period of Muslim rule, likewise in all the countries of the Balkans after the Turkish conquest — even the Muslim Albanians and Bosniaks are descendents of Christians who stayed. Egypt was majority Coptic Christian for centuries after the Muslim conquest.