Do you know how it was decided that Ahmadis are non-Muslims?
The decision was made in the parliament and Qadianis was given a chance to debate with Muslim scholars. The question that was asked to Ahmedi elders “Do you consider other Muslims who don’t believe in Mirza Ghulam to be non-Muslims?”… the response was “yes we do believe that those who don’t believe in him are kafirs”. For the same reasoning, just like for Ahmadis if other Muslims are non-Muslims, for them they too are.
The principle of compulsion will NOT hold if a person VIOLATES majority’s RIGHTS (Rights to Honour, Property, Freedom), in that case, the AUTHORITIES will COMPEL that person to make amends/repay/or suffer similar pain. Similarly, taxes (which are received from the rich and spent upon the poor). In all these cases, the injunction of the Quran will supervene the Principle of NO COMPULSION, for obvious reasons.)