Hello Ivor
1. the display preferences for the diagram allow you to choose the font for primary key attributes; this defaults to 'underlined' as you said. So, I assume that the default font is not what you would expect. Arnaud suggest that you check the format of the symbol, instead I suggest you check the preferences for the whole diagram
- right-click the diagram background
- select Display Preferences
- select 'Table' on the left
- select the 'format' tab, and proceed as per Arnaud's instructions
- click on OK, then apply to all symbols
2. There is a filter button that allows you to choose which columns to display - you can find instructions in PD help, just search for 'Customizing Object List Columns'. The customise and filter button is two buttons to the left of the Excel export button.
3. In the CDM and LDM, you draw relationships from parent to child entity; in the PDM you draw them from child to parent table 