Why does Finder need me to authenticate its every action? I have to enter my password to create, delete, or move any folder or file. It sure is getting annoying. Why is this happening? 

This is happening in a new user account that I created today. It has administrative privileges, and I have deleted the old one. (The authentication problem didn't happen in the old account.)
Sounds like a permissions issue.

Press Command+I while the highest level folder you want to be able to access.  At the bottom of the info dialog, be sure the lock is unlocked.  If the user name you wish to access the files from is in the list, be sure it is set to Read &amp; Write.  If it is not in the list, press the plus sign at the bottom of the dialog.  In the dialog that opens, select the user name you wish to access the files from and press OK.  Then, be sure that this user has Read &amp; Write access.  

If this doesn't solve your issue, please let me know.