> it's not really the Gimp's fault with this particular problem.
Well, I'm sure you understand that while this is technically true, in reality it doesn't matter whose fault is that.
> I have not tried the developer version of Gimp yet, but this guy says he is using single window mode in 2.7.1, but it's not turned on by default.
Thanks. No, there wasn't such an option in mine's install, but I've just updated from that PPA to 2.7.3-something, and there's that option now indeed! So I turned it on, and I can say gimp looks MUCH better now! Utilities now occupy left and right vertical screen areas, which you can resize with splitters to give more or less space to the canvas in the middle. Also, instead of different windows for different images, there are tabs now. Overall, this looks so much better, you wouldn't believe!
However, right now this works glitchy as hell. Oh well. I'll wait for 2.8. That's all very promising. Thanks for a pointer!