Markus, thanks for the brief reply.
1. For Extended SP's, I go to Database Properties->Security-->
Roles-->Database Roles--> Public--> Properties-->Securables
Here, I see a number of Extended SP's. I had to select each one and then remove EXECUTE persmission; and this has to be done for all user db's. So, is there a way to do this either by query or GUI to revoke execution permission for all Extended SP's?
2. For Public role restriction, In Server role public--> Properties-->Permissions -->i see tcpip, named pipes etc only with CONNECT option enabled. So, if i need to remove all permissions for Public, should i go use Server role public or Database role public? In DB role public, as said above, it has execute permissons for most sp, connect etc