1) and why is this an issue? But if you are using fields of type calculation and the check box ("do not evaluate if all the referenced fields are empty") is selected, you should not see any values in such fields until you enter data into a field and the record is committed.
2) You should use a value list format that does not permit the entry of unacceptable values.
And the large number of fields all in one record suggests that your basic design could be improved with the use of related tables where your questions are loaded in one table, one record for each question and your responses to them are loaded in a related table, one record for each answer.
See this thread for a discussion of that design approach: Need aid on generating a report from a survey layout.