In the interests of accuracy, I'd like to talk about the Christian Heaven. Though I now consider myself an agnostic, I went to two years of bible college (think the Fundamentalist version of seminary). To the best of my recollection, the only substantial description of Heaven appears in the last two chapters of Revelation, a book that even in Fundamentalist circles is acknowledged to contain a lot of symbolism.
There are two parts to this description. The first (Rev 21:3-7) talks about what God is going to do in Heaven: "He will wipe every tear from their eyes. There will be no more death or mourning or crying or pain, for the old order of things has passed away." and so on.
The second part (Rev 21:10-22:5) discusses the appearance of the city in a manner that nearly all theologians would interpret to be symbolic. The city has walls of jasper (God's appearance is previously described as jasper, earlier in the book), and is built of pure gold (a reference to the purity of the inhabitants; the book earlier describes the trials they've gone through as purification, so that all the dross would have run out and only pure gold remains). The numbers given are all based on 12 -- both the number of the tribes of Israel, and the number of the apostles. Likewise, the listing of gemstones for the foundation is derived from the list of jewels representing the twelve tribes in the high priest's breastplate as described in Exodus. There's more I could say here, but I doubt you care too much; suffice it to say that the whole thing's symbolic.
The "singing hymns" part actually comes earlier in the book, in Revelation 15, where the apocalypse is still occurring. There's no mention of it in the last two chapters, and certainly no mention of that being all you do forever.
There isn't actually a lot of description of Heaven in the Bible, perhaps for good reason. Apart from these two chapters, the only other stuff we have to go on is some sayings of Jesus in the Gospels. Nothing that I recall about "you'll never have to work again", though there was a lot about giving rest to those who are weary and heavy laden (and if that's not a good description of a peasant's life, I don't know what is).
My point for bringing this up isn't to convince you that the Christian Heaven is great -- as I said, I don't believe in it myself anymore. Rather, I find that people typically make better arguments when they actually know what they're talking about, and it may assist you in railing against the Christian Heaven to know what it actually is said to be.
Your post explains how the bible describes heaven. However, when I hear the phrase “Christian heaven” I tend to take it to mean “heaven as Christians today understand it”. You may well be right that the bible doesn’t directly imply that it includes singing hymns for the rest of eternity, but clearly it is widely imagined that way, otherwise we wouldn’t all have heard that idea.
So this is Utopia, is it? Well
I beg your pardon, I thought it was Hell.
-- Sir Max Beerholm, verse entitled
In a Copy of More's (or Shaw's or Wells's or Plato's or Anybody's) Utopia
This is a shorter summary of the Fun Theory Sequence with all the background theory left out - just the compressed advice to the would-be author or futurist who wishes to imagine a world where people might actually want to live:
The simultaneous solution of all these design requirements is left as an exercise to the reader. At least for now.
The enumeration in this post of certain Laws shall not be construed to deny or disparage others not mentioned. I didn't happen to write about humor, but it would be a sad world that held no laughter, etcetera.
To anyone seriously interested in trying to write a Eutopian story using these Laws: You must first know how to write. There are many, many books on how to write; you should read at least three; and they will all tell you that a great deal of practice is required. Your practice stories should not be composed anywhere so difficult as Eutopia. That said, my second most important advice for authors is this: Life will never become boringly easy for your characters so long as they can make things difficult for each other.
Finally, this dire warning: Concretely imagining worlds much better than your present-day real life, may suck out your soul like an emotional vacuum cleaner. (See Seduced by Imagination.) Fun Theory is dangerous, use it with caution, you have been warned.