missing from feedback but present in questionnaire (in random order)
-> question name for the header of the columns in the download document
-> "Other" option for multiple choice questions (radio button)
-> "Other" option for multiple choice questions (check boxes)
-> rate question (with excellent "Type of rate scale")
-> number of integer and decimal digits for numerical questions
-> "Min. forced responses" and "Max. forced responses" for check boxes question
-> multiple (periodic) submit allowed for "not anonymous" users
-> Save/Resume option
-> custom themes (is it useful?) 
-> Public
-> Copy existing (is it useful?)

missing from questionnaire but present in feedback (in random order)
-> Informations (very useful, IMO, but needs be improved)
-> ranges (very useful, IMO)
-> Templates

missing from feedback and questionnaire
-> conditional branching (it has no sense this feature into the database module, IMO)
-> fields with restricted availability (only for user with capability: canaccessprivatefields, for instance)

missing from feedback and questionnaire but present in database
-> teacher can edit records added by students

missing from feedback and questionnaire and database too
-> date field to get dates before January 1, 1970
-> date with only month and year (When did you buy your last car? January, 2002)