We need to teach RE, we need to teach the principles of citizenship, we need to teach ethos we must teach the law of the land we must even teach the principled campaigns of the BHA and NSS we must teach the great ethical movements and then we should go into moral realism and moral irrealism.
A disconnect between dogma and praxis of moral irrealism should be left to when such contradictions can be more maturely held.
Then I think we are basically in agreement.
Thinking about this over the past day or so, my feeling is that we should embed all these elements under the broad umbrella of 'citizenship', which would be a developing curriculum strand throughout compulsory education ages. This would, of course, involve learning about religions (the major ones, not just a single one), both in terms of culture, practice and belief but also linked to morality and ethics - the latter needing to be taught alongside non religious ethical approaches.
It would also include what is currently describes as 'British Values' (I hate the term as they are no more British than most other developed nation values) eg. respect tolerance, rule of law, democracy elections etc etc. We would also include the PHSE strands too.
All aspects need to be taught in an age appropriate manner.
This citizenship strand should be compulsory and without parental opt out.
If kids want to learn more about religion etc they are free to study RE or Philosophy and Ethics at GCSE or A level.
If faith schools are to continue to exist they should also be required to cover this curriculum.