Is there a way to retrieve password stored in Safari as it is possible to do it in Firefox ?
Safari stores its passwords in the OSX Keychain. Open
/Applications/Utilities/Keychain Access.app, select the "Login" keychain (this should be default) and select "Passwords" under "Category". Doubleclick an entry and check "Show password"; you'll be asked for your login keychain password (this is usually the same as your account password).
(For a while I was using an add-on for Firefox that used the Keychain, but it was highly broken.)
Another solution is the Safari extension LastPass [see lastpass.com]. This is also a Firefox addon. You could migrate your passwords and secure notes to LastPass and they would be available on any browser and on any machine. This extension was scrutinized by a security expert on the podcast "Security Now" episode #256 [show transcript at http://www.grc.com/sn/sn-256.htm]
Actually they are available more conveniently in Safari itself:
Preferences... -> Passwords