1) Jasmin is an SMPP router not a "Service provider". You need a service provider to forward your SMS and send them for you. Same as an ADSL router that needs an ISP to connect you to the internet. You cannot "just send SMS" for free if you mean than.
2) If you were curious to read the manual before ask you would have seen that all your answers reside there
At the same page you can clearly read the NOTE:
Setting none value to a user quota will set it as unlimited quota. so
mt_messaging_cred quota balance none