How can i install themes for qt3 and qt4 without need to install kde? And, is there any way i could use not qt themes for GTK (GTK-QT engine), but GTK themes for qt apps?

You can't as far as I know, QT is a KDE app. You can use 3.5 or any version, but the two go together. I'm not sure why you would want to use one without the other. You know you can use both KDE & Gnome together, right?

GTK is a Gnome app. QT is KDE. Not sure on that one.

I mean something like gtk-chtheme for GTK as well as simply by creating/editing .gtkrc-2.0, but for QT. As you see, i don't need GNOME to change GTK theme, i guess i shouldn't have to have KDE to configure QT theme. The question is "How then?".

Edit:
I found qtconfig utility, but how can i add a theme to the list?

Qtconfig will help as you already found. To add a "theme" to the list you need to install a new "so-called" kde style, which more correctly is really a "qt engine", or style, or whatever you want to call it.

You might really want to check the qtcurve style, which has native versions for gtk+2, qt3 and qt4.

Nope, QT is a general purpose toolkit, as set of libraries that can be used to build anything you want. Probably the biggest project ever built around the QT libs is KDE. So, if anything, it's the other way around: KDE is based on QT, and not the opositte.

If you mean KDE and QT, the reason is simple: not all QT based applications are part of KDE. There are pure QT apps that do not link against kdelibs nor any other kde component. You can get an idea at qt-apps.org. Some famous apps using QT (but not kdelibs) are Opera, Skype or QT.

The same applies here. GTK is a general purpose toolkit that can be used to build applications, and not all (not even *most*) of them are part of Gnome. GTK stands for Gimp ToolKit, because it started as a set of libs being the foundation for the Gimp. Think of bluefish, the gimp itself, even firefox and thunderbird, all of them use Gtk for one or another thing, and neither of then is part of Gnome, not even related.


Qt4 has this feature, it can use the gtk+ theme, you can choose it in the list of styles in qtconfig. And this feature really works perfectly, unlike gtk-engines-qt, which never worked reliably, and that never looked quite the same than a native theme.