re Voland's point 1. As Ledswinger said there is no reason not to give charities an exemption.
Oh yes there is.
The local sports organisation around here is a registered charity and not,as one would expect a council run organisation which its name would imply.. With twenty or so physical facilities, and likely hundreds of staff*, they have a substantial revenue and wages bill. They must have some overriding reason for being a charity.
Why on earth should they be exempt from operating PAYE and paying Employers NHI?
*As well as some who are deemed to be "self employed" but are clearly under full control of the organisation as to what work to do, when to do it, and precisely how to do it. Borderline tax avoidance.
And no doubt, 1000's more are of the same type.
Take a traditional charity, one of the big ones. Oxfam, Help the Aged, et al. I don't know the fine detail but many nowadays pay top salaries upto and exceeding six figures. Why should that be tax and NHI free?