Google Spreadsheet/ Google Site Scripting

I have a Google Spreadsheet that contains the contact information for some people. 1. I need to be able to allow each person to update their own information that is contained in the spreadsheet, but they should only be able to see their own information and nobody else (via web form or something). 2. I also need to be able to send an email to all of the people listed on the spreadsheet to have them update the information. 3. There should be a column in the sheet that identifies who updated the information last (me or the user) and the date and time it was done. 4. I also need to be able to continue editing the spreadsheet via Google Drive as needed 5. Most users will not have Google/Gmail accounts, so there would need to be some method of security within the spreadsheet, or when the email is sent out there is a custom link each user clicks on that takes them only to to their information / also may need a password or something (can be contained in the spreadsheet)?? Need done in 48 hours!