Just wonder how to set quota on MySQL DB for a account:

-limit #DB/account
-limit #tables/account
-disk space/account

Many webhosting company do it, so I guess it's possible with cPanel or other control panel.

Any awnsers, guys !?!...

Im sure uts possible to do tin in mysql, doing that via cpanel im not so sure.
IIRC dosnt the mysql db size count towards total account quota?

Because databases are owned to mysql, they are not counted towards the client. There is a script in /scripts to set permissions to the user. Most hosts set this on a cron to run every day or so and the script chowns the accounts to the proper owner and then it counts against their quota.