Tbh, you just sound as 'me,me, me' as you claim all the 'problem' people are.
People are entitled to annual leave, so if Good Friday/Easter Sunday are important to them, they can book it off. People do that for other dates that matter to them.
And why is it only retail workers (in large shops) that bother you? People who work in tourism, medicine, the emergency services, taxi drivers, etc all have to work on Sundays and religious holidays (at least potentially). The worst thing about the laws are that they're totally irrational. Working in a big shop (that's open to the public) is no different a task than working in a small version of the same bloody shop, or a garage, or a fast food restaurant, but the law only prohibits or curtails the working in a shop above a totally arbitrary size. The law even allows working in the same big shop so long as it's not open to the public. The current laws actually have nothing to do with protecting people from working on Sundays/religious holidays.
I really don't understand why you need everyone else to observe your religious holidays for you. And the 'Christian country' stuff is nonsense. I'm a British citizen (as everyone in my family has been for generations) and I'm not Christian. Why should my opinion on whether religious observance should be forced on the populace matter less than yours?
It would be different if I chose to move to Pakistan (etc) but I was born here and I'm allowed to question the stupid way things are done here.