Whether an application fits on screen of course depends on a lot of variables, like whether there's a big panel taking space, or the active theme and even the translation. I'm afraid I cannot guarantee that Krita will always fit in the minimum resolution given these variables. I know it fits for me, in English, using Oxygen and OpenSUSE...
About numerical input of HS(V,B,etc) -- fair enough. Nobody asked for that before, and apparently artists don't need that kind of precision, but it would make a good improvement on the specific color selector. I have created https://bugs.kde.org/show_bug.cgi?id=289367.
Of course, you mention how frustrating it can be to file bug reports and see them closed as "won't fix", even if there's a good reason for closing the report, as in the example you have given. I can only say that there are wildly different standards for handling bug reports between projects and even within KDE. Nobody has ever closed a Krita bug report because the discussion has become acrimonious, for example, and most bug reports receive at least a reaction within a week (most often on Saturday, because that's when I sit down and triage.) In other words, it's up to the maintainer, and since I try to be a conscientious maintainer, I would very much appreciate not to be tarred with the same brush as other maintainers who might neglect bug reports.
(This is a fun graph, made by one of our developers: http://i.imgur.com/4qLWK.png. It shows the bugs on the y-axis, and then on the x-axis a pixel for every day that the bug wasn't fixed. It would be more interesting to see when we first came back with a reaction to a bug report, but well, it's just statistics anyway. Draw your own conclusions...)
Finally, I do agree that updates don't land on people's desktops quickly enough. With Calligra we were aiming for a four month release cycle, but there's always more to do, and so the schedule slips and slips. Right now, most professional and semi-professional users actually compile Krita from git master... (Which kind of shows how eager those users are to get the latest features -- and of course, also the bug-fixes we do for them.) This situation is not ideal, but I don't see how it's "brain-dead" either.
Btw, the issue with the ellipse tool leaving traces of garbage on the canvas is fixed.