In Quickly/Glade, is it possible to keep the text (well, labels) centered, so when I maximize my program's window, the text stays centered? It's probably something easy to do, but I have been unable to find where to auto-adjust the position. Any help would be greatly appreciated.
Generally this is caused by how you are creating your layout. It sounds like you are using a fixed layout (as your top-level layout) which will make it much more difficult to do.
The best thing to do is to create a fluid layout by starting your layout with a GtkBox within your GtkWindow. Much like this:
This will make your layout fluid and allow for your text to become centered within your window. If you have to remain with a fixed layout, you'll have to attempt to center the label problematically.
If you are using a GridLayout, I believe you'll need to turn on "Horizontal Expand" on the label to get it to fill the unused cell space. However, its been awhile, so don't hold me to that.