...are RY pilots free to fly as like a "premium" airline?
In general no. They are denied union recognition, must toe the party line and they will do what they are told. Going sick is also pretty risky. And don't be late too often. They are run by what could at best be described as bestial, brutal, feral management. But as long as people want "cheap" flights, Ryanair will stay in business.
In return, some of RYR pilots are the best paid pilots in the world. Those on the older contracts will receive in the order of €130,000 to €150,000 this year. Out of this they have to arrange their own tax, pension, car parking, accommodation, medical, licence, uniform, meals (at work) etc. They will also have a stable roster pattern and have a degree certainty in their lives. I'll also stick my neck out and suggest that they some of the most competent pilots as well, which can be demonstrated by their record.
However, I'd prefer to walk than fly Ryanair. I don't like MOL and what he stands for. So I do what MOL does and that is, not fly RYR but instead go with another carrier.