- selecting all edges: select one, then press Ctrl-A
- to change the default edge type to one with no arrowheads at all: in the "Palette", open the palette section "Edge Types", double-click on the first one (the one that has no arrowheads); new edges that you create will have no arrowheads
- to adjust edges that are already in a diagram: select all edges (see above), then in the "Properties View", under the "General" section, in the "Source Arrow" and "Target Arrow" dropdown change to the rendering that doesn't show an arrowhead
- in the "Preferences" dialog ("File" menu > "Preferences..."), on the "Editor" tab, use options "Edit Label on Create Node", "Dynamically Adjust Node Size to Label Size"
give an example
- see also: "Help" menu > "Help"