I stopped developing for Sage largely because reviewers wanted me to use Mercurial queues.
I don't know about the reviewers you worked with, but when I'm reviewing tickets, I only care about what kind of patches are posted -- I don't care how they were created. A clean diff, ticket number in the commit message, proper username...that's what I want.
Is there a way to accomplish what Mercurial queues does without the learning curve?
Right now, probably not. But I did find that once I figured out queues, it was the most natural and easy way to work. Take a copy of Sage, qimport a patch, test it, pop and delete it -- and my copy of Sage is just like it started. Things get a bit more complicated with the sage-combinat stuff, since they have a huge queue and use guards and all that -- but you can ignore that stuff.
It sounds like much of your confusion would be cleared if you could sit down with someone and have them show you things -- or maybe a good chat on IRC with a shared screen session. Read the Mercurial book and ask questions. I think you can understand queues without too much trouble.