I solved the problem by retrieving all contacts into the MacBook Pro Address Book from a back up in Time Machine. I also deleted MobileMe from System Preferences and from the Preferences>accounts in iCal (in the Mac), and in Settings>Mail,Contacts,Calendars>Accounts (in the iPad2; this way I god rid of two cards per contact in iPad 2 Address book). Then in iTunes I selected the option to replace the information on the iPad with that on the MacBook Pro.
Deleting MobileMe throughout bot in the Mac and in the iPad seemed to clean much of the problem.
Thus, now I have all data (contacts in Address book and events in iCal) complete and organized in all my devices; I am still syncing through iTunes with appears safer than iCloud for the moment.