Q. In Optimizing report, I can enter up to 1000 characters for keyword Meta Tag. But in the site info of web profile, the character limit is 200, why?

The web site Profile details you enter in the program and the Meta tag of your web site are two different things. Although both have the title, keyword and description, the site info of your web site profile (see Enter Site Information for details) will be used for submission to Directory Engines like Dmoz.org while the Meta Tag details will be used for Spider search engines, like Google.