Keyboard Shortcuts - for other than ordinary programs or files

If you add a new widget via double-click, it is added to right.
But you can move it when the toolbox is open, the mouse cursor will change to the “move arrows” when you hover over a widget, just click and drag to move it. You can only drop it to a fitting place, you should see the other widgets making space in real time and create a new space for it if you are at such a fitting place (between two other widgets).
Dragging a widget from the “Widget Explorer” to the panel works the same way.

Regarding the size of the font: changing this is not possible, I’m afraid.
It always adapts to the available space. If you make the panel higher, the fonts for both time and date will get bigger as well, but you cannot change the ratio.

to kde.org. You do understand the kde is not the same as openSUSE. openSUSE only uses and maybe does minor adjustment to the KDE.org programs

there numerous mailing lists

You should have a kinforcenter icon on the default desktop (think of it as mycomputer) If you removed it is is also in the menus under system-more programs

There’s no point in doing that.
KDE4’s desktop is feature frozen, in bugfix-only mode, since over a year.
And it will be abandoned completely by the KDE developers in a few months.
So this is definitely not going to be implemented (for KDE4, that is).

In Plasma 5, the clock widget in particular has been completely redesigned, so you’d better try it there first before you file a feature request.

To suggest features for KDE, there are basically two places:
KDE’s bugzilla: http://bugs.kde.org/ (mark your “bug” as WISHLIST)

Or, maybe better, there’s a “Brainstorm” section in KDE’s forums, where you can suggest ideas that can be discussed then and voted for/against:
https://forum.kde.org/viewforum.php?f=83&sid=2fef381ac9479bda81682a8874135e5c

Mostly off-topic, but how do I find out which verions of Linux, KDE, and Plasma are currently installed?

You can look in YaST->Software Management e.g., KInfocenter should tell you, and there’s an “About xxx” and “About KDE” entry in every KDE application’s “Help” menu.

And is there any equivalent to Windows Device Manager where I can get a concise list of what hardware is hooked up?

There’s KInfocenter that shows some information about the hardware as well, and there’s YaST->Hardware->Hardware Information.