Using PIVOT to address the following requirements?

Hi All -
I am hoping some folks here can give sound experience advise from those having working experience with Oracle PIVOT clause introduced in 11g. 

Q#1:  Is there any physical limitation to the # of rows I can pivot into columns?

Q#2:  In consideration of the PIVOT IN clause, can I pivot every row value targeted for PIVOT?  Reason for this question, I am trying to pivot responses to a survey - so each participant response is stored as row-wise.  The requirement is to create a column-wise presentation to a single row for each participant.

Example:  A 5 participants complete a survey with 100 questions.  Assuming every question is answered, there are 500 rows in the table.  The columnar requirement is to pivot the table.  A pivot would result in 5 rows and 101 columns (participant id + 1 column per each response);