A: Not necessarily. Actually, we recommend that, instead of the DBA role, you grant discrete privileges; that grants everything! Within Toad, we try to use USER_ and/or ALL_ where possible, but a few things like tablespaces only offer DBA_ views. In those cases, all you would need is the SELECT_ANY_CATLOG role.
Chris Reyes previously worked for Quest and Dell managing the Toad World site and Program Management for various Toad applications. In my spare time, I like to play vintage base ball (1880's rules) and do 3D printing.