To the topic title - do I wish people would just give up religion - I answer, "absofuckinglutely". But religion is not the root of the problem, I think. Religion is a symptom of a bigger problem - faith based belief. And I'm not talking about the kind of faith people have in their spouses, or in technology ("you have faith airplanes will fly"), or in your favorite sports team. All those kinds of faith - if you even want to call them that - are justifiable.
You have faith in your spouse because you have spent time with him or her and have observed a pattern of behavior that gives you reason to trust them. You have faith that airplanes will still fly because in 2000 or so years of various levels of observation, the laws of physics have not changed. And having faith in your sports team is more about loyalty than blindly and irrationally believing they are the best.
The faith I am talking about is the blind faith so many religious people deny they have, yet describe their faith as exactly that. Believing things without good reason or in the face of contradictory evidence. This is not exclusive to religion. You see it all over the place. Most politics is rooted in faith based beliefs. By extension, a lot of people's economic views are entirely faith based.
Sometimes the justice system works by faith. There was a prosecutor in NJ in the last year and a half or so who wanted to procedd with murder charges against a man because he once owned a car that fit the desription of one that was involved in a drive-by murder. The man had a receipt from a junkyard that showed he junked the car months before the shooting and the police had used cell towers to triangulate the man's cell position to be 90 miles away from the shooting at the time it happened. Nevertheless, the DA was sure this was the guy and promised to carry the prosecution forward. How? Faith.
Faith based beliefs are inherently resistant to correction. They tend to stand in the face of contradictory evidence. As such, they are denials of reality and enemy of the truth. And this is why I take issue with them. So, at the root of it, I wish people could evolve beyond all faith based beliefs. If they do that, religion will go with it.
However, we cannot
evolve beyond faith based beliefs. There is nothing selecting for reason and against faith. There is no mechanism making people who believe ridiculous things for no good reasons produce fewer children. In fact, in this country, that sort of thing is encouraged. So, the other questions come in to play...
How far would you go to SUPPORT their right to peaceably worship as they see fit?
It depends how they see fit. If they want to say some prayers to Lord Ummagumma in the privacy of their home, have at it. If they want to encode their stupid beliefs into the law in any way, then I say rebuild the Collesium and feed the sonsabitches to crocodiles.
Would you lift a finger to help if their rights were being denied?
It depends how their rights were being denied. If someone was trying to punish them for praying to Lord Ummagumma in the privacy of their homes, then yes, I would want to help them. Or if some jackhole was trying to make the Ummagummites pray to a different god, not of their chosing, in school, then yes again. Atheists and religious minorities actually have a history of cooperating on keeping the government secular, issues like prayer in school.
However, if the religious were being fed to crocodiles in a new Collesium because the religious were trying to take over the legislative system, then no, I would not help them. I believe I would buy front row seats at the Collesium.
Do you see this as a civil rights issue at all?
I'm not sure what you mean.
How much legal and ethical ground will you concede, in good faith, to the believers so they are truly free to live as they choose, even while you assert that they're doing it all wrong?
If we are talking about reality and not a fantasy world where I am some kind of magic weilding king who can bring physics to its knees and bend the minds of men to my will, then I think lots. By "lots" I mean we have to cede as much ground to all religious kooks as possible as long as it does not intrude on the rights of anyone else
. If they are against praying on sundays, then they shouldn't have to pray on sundays. But we also should not stop anyone else from praying on sundays. 
I think this is the way we currently handle it and it has its obvious problems. For one, some segment of the religious population is completely uninterested in that agenda. They want to make the state into their tool for enforcing orthodoxy. For two, faith based thinking degrades all discussion and gets in the way of making good decisions.
But I don't know how to fix those problems. I would like to say if you cannot at least compartmentalize your faith thinking, you don't get to vote or occupy any position in government in any way. But that sets up a precedent for the other side to do the same to anyone who disagrees with them. Which means we would likely be on the other end of the stick.
This is not actually a matter of principle to me. It is utilitarian. Until we can be sure the religious majority will not use their power against us, we have to grant that everyone has the right to believe the things they want. Goose and gander. But once you make me your magic weilding king, all bets are off.