Use the UNITS command, and chose Architectural units for Ft -in-fractions, or Engineering units for Feet - inches.decimal. then look into your Dimstyles, and set one up that works with the architectural units setting
>> Rather than defaulting to ISOPEUR, can I request that the system finds a different font as a default, and ignores ISOPEUR when I'm using RomanD?
As far as I can find out, that is not possible. ISOPEUR is apparently hardwired into the application as the go-to font for missing symbols...
It's possible that the dialog is appearing off screen. Try hitting the <alt><Spacebar> combination, and then M for move. If the dialog is offscreen, you can the use the arrow keys to drive it back into visibility