No, I don't think you're asking too much here at all, and I totally agree with you. Take a look at Nix OS - it's a Linux distro that, if memory serves, comes with those kind of guarantees as to how it handles packages, installations, etc. No idea how useable it is for a desktop environment as compared to Ubuntu, but you might find the general approach appealing (again, if memory serves, please pardon me if not).