from http://fedoraproject.org/wiki/KDE

Add the following line to /etc/sysconfig/desktop:

/etc/sysconfig does not exist...yes I was su

DESKTOP="KDE"

Idea.png
If this file already contains a DESKTOP entry, you must replace that entry.

To make KDM the default display manager, add the following line to /etc/sysconfig/desktop:

DISPLAYMANAGER="KDE"

Have you tried creating /etc/sysconfig? I find it quite concerning that /etc/sysconfig doesn't exist - however with the large number of recent changes carried out by Fedora, including systemd, I wouldn't be surprised if those instructions are out of date.

also on starting F16 install, there is a distorted message ...something to the effect yhat systemd failed to start

I would recommend asking on your distributor's forums about that issue.

with all due respect, I'd say yes but no

these settings in /etc are made by a KDE install and could be "kde"

KDE does not provide packages, the distributions do. And many customize them to be better integrated in existing setups/build systems/customizations/whatever.
Thus, you'd probably get better support if you contacted you distribution directly.

I know what they will say:

contact kde

The determination of which Display Manager to use, as well as any default desktop configuration it may have is almost always the sole domain of the distribution.

KDE pretty much only comes into effect once you actually login.

/etc/sysconfig doesn't exist by default on Fedora. You need to create it. If it doesn't exist Fedora uses gdm as the displaymanager. If gdm isn't installed it uses kdm if that is installed.
I don't use the 'DESKTOP=' setting as kdm will select the previous Desktop unless you change the setting on the login screen.

clariceoshea wrote:these settings in /etc are made by a KDE install and could be "kde"

Nope, I haven't got one either (and yes, I'm on KDE)

Go with ozjd's advice and you should be fine. Otherwise you could just ask on your distro's forum where to determine which login-manager to use (as there are plenty of them).