Placement
This option governs the placement of the label in relation to the element the label belongs to.
The placement property consists of model and position due to the way the underlying yFiles library handles label placement. This implementation detail is exposed here so yFiles customers will recognize the yEd placement options.
Alignment
This option governs the placement of the text inside the label bounds. The effects of this option are only visible for labels with multiple lines of text.
Configuration
This option determines the label feature set.
"Standard" offers supprt for displaying and icon and rendering HTML formatted text.
"Cropping" offers automatic text cropping and text wrapping. Both, automatic cropping and wrapping do so in the bounds of the label. Thus the effect of the cropping configuration will only be visible with "Size" set to "Fit Node Size" or "Fit Node Width".
Again, this is property is exposed here so yFiles customers will recognize the yEd configurtion options.
I guess the "center text" behavior you are looking for is achieved by setting both placement to "Internal: Center" and alignment to "Center".
That said, yEd is not meant in any way as a replacement for Power Point. If at all, yEd is more like an alternative for Visio.