How Much REDO Would Increase If Enable Supplemental Logging

we  use  Oracle11gR2 on Win2008R2 .By erroneous operation of OracleDB, there was trouble that we could not log in to Application(Oracle Insight) running on Oracle11gR2. I looked up and understand by running the below ALTER DATABASE ADD SUPPLEMENTAL LOG DATA we can find the SQL statement that was executed in the past from SQL_REDO column of V$ LOGMNR_CONTENTS table, undo SQL statement to rollback from  SQL_UNDO column of V$ LOGMNR_CONTENTS table. But , we are concerned about the adverse effect of enabling the supplemental log because it is production environment . I heard the contents of the REDO log will increase if we enable supplemental log. 

Q1-How much the REDO log would increase roughly if you enable supplemental log ? ( I am concerned about the issue of the capacity of the  REDO log  and the problem of DB performance . ) 

Q2-Is it necessary to restart the DB instance to enable supplemental logging after executing the below ?ALTER DATABASE ADD SUPPLEMENTAL LOG DATA.

Q3-Is there any other adverse effect we should care  if you enable supplemental log ? 

Q4-Logminer is usable if DB is running on no-archive mode ? In my understanding , it is possible if  you enable supplemental log and have the REDO logs we would like to analyze.