Re: so... kde3.5 was dumped for kde4 why again?
What version of KDE 4 are you using? KDE 4.0, 4.1 or trunk? Which distro are you using? KDE 4 has been undergoing extremely rapid development so I can't tell what you are looking at without knowing what version you are using.
If you are using KDE 4.1 or trunk, to move the task bar you need to first click the little yellow thing on the right side of the taskbar (commonly called the "cashew" although I think it is supposed to be a ball of plasma). That will pop up a bar that allows you to resize the taskbar both verticallly and horizontally. By clicking and dragging on the bar you can drag it to the left and right edge, or the top if you want.
The alt+F2 pops up the krunner menu. Start typing the name of a program in there and you can launch it. It can also do a whole lot of other things like mathematical calculations, spell checking, and integrates or will integrate with various programs like email, amarok, and power management.
The thing in the upper right is for switching what are called "containments". Basically a containment is a set of widgets. For instance you can have two containments with different collections of widgets on the desktop, different location, layout, and content of the taskbar (actually it's called the "panel" in KDE). You can use it if you want, but it is not fully implemented. They will make it easier and more useful to switch containments in KDE 4.2. In future versions KDE will automatically switch containments based on what you are doing. For instance you could have a word processing containment with character map widgets, your documents folder, dictionary widget, etc. You could have an email containment with your contact, email monitor, etc. And so on and so forth. This sort of thing will be pervasive, the entire desktop environment will be able to tell what you are doing and reorganize itself for that task. So instead of approaching things in terms of desktop or windows, the system will approach them in terms of tasks and will optimize the desktop, window, taskbar, and other things for that task.
Make sure you check out the "Add Widgets" toolbox. Note that most widgets will work on both the desktop and panel, and some will behave differently depending on which you put it in (better support for that has been implemented in trunk but not KDE 4.1). So for instance you clock could be on the desktop, the panel, or both. Your "show desktop" icon is in the "add widgets" toolbox, as is your program launcher menu, shutdown/logoff buttons, system tray (note that you can currently only have one system tray at a time, they are currently fixing this but it isn't done yet), task manager (you can have a bunch of these), virtual desktop switcher, removable media menu, etc. I don't know exactly what widgets you have since once again it varies depending on your distribution and version.