Re: Am I alone?
When I began to read your mail and your recommendation to stick with 3.5.9 I first thought you were going to complain about plasma configurations disappearing, K3b, Kdebluetooth, Quanta, Nepomuk, etc, in KDE 4, well, more exactly about their inexistence or miserable status 2 years after KDE 4 began to make our "dream come true"; I was thinking "wow, a guy who thinks we have enough eyecandy and it's time to go efficient and useful, and has the b*lls to say it publicly without fear to be calle a troll, or to have answers like 'stick with Windows or buy a Mac', 'KDE is made by volunteers, do it yourself or shut the f*ck up', and such", hehe. But now I think you are not exactly a critic but a very "bad-lucked" guy, :-/.
Most of those issues you mention are quite rare, I'm not the most experienced user, and by no means I am a programmer or software "technician", but I hadn't read things like those in forums blogs or whatever, honestly.
But there's one of your issues I share, at least partially; hte Konqueror freeze. AFAIK it is a problem with Flash, but closing the Konqueror window solved the problem, temporally. Just Ctrl+Q worked for me. Take a look to this post, perhaps it may help you:
Iceweasel has never presented such annoying behavior, althoug it decides" to reside in memory and eat my CPU after closing it, and I have to kill the process (I think I'll try Firefox, which besides is better adapted to my regional circumstances), but, again, I just can think you are alone with you IW issues. When I log in, my previous IW session restores with all its tabs, size and position. You can always tell Kwin to remember any program's windows position and size, just right pulse on the title bar > Configure Window behavior > Window specific, or something like that, the last one (sorry, my KDE is in Spanish) and there create a new rule for Iceweasel. This should work.
I don't usually work with more than 3 desktops, and my laptop doesn't have all those buttons, so I can't say about this.
Kmail works flawlessly for me, and for some friends who also use KDE 4; our colums stay as we configure them, so, once again, I think you are alone.
I'd follow Modestas advice, I'd even would try a complete fresh installation in a clean partition if "renewing" your .kde directory doesn't work. If not, you can always try the "rusty" efficience of Gnome, hehe, ;).