You need to drop and create it again.

Need more information.

If you want to have distinct values u can use distinct otheriwise you want aggreate values for the columns you need to use group by clause. All that depends...

You can transfer the data using ssis into stage table on target server and update.

if the delay is acceptable and it is an repeating task.

Could you please provide more detailed information such as the version of your SQL Server?

Check the following link

http://stackoverflow.com/questions/3824461/ssis-xml-task-with-a-for-each-loop

What is the functionality of jobs? Is that jobs are calling any SP's?

Did you tried using table hints on the tables? and what is MAXDOP value now?

Yes, you can

Check the following link:

http://social.msdn.microsoft.com/Forums/en-US/sqlanalysisservices/thread/1012a7dc-ad8a-431c-a138-54a173e31016/

Look at the following links

http://msdn2.microsoft.com/en-us/library/ms345235.aspx

http://forums.microsoft.com/MSDN/ShowPost.aspx?PostID=83229&SiteID=1

Not clear

Please check the following link:

http://www.replicationanswers.com/MergeNonConvergence.asp

Please check the following link:

http://www.simple-talk.com/sql/t-sql-programming/parameter-sniffing/

check the following link:

http://msdn.microsoft.com/en-us/library/ms152532(v=sql.105).aspx