3 in parallel and each (4) of them in series? 3P4S
Yes, i have not experimented with how low it can be set but probably as low as you would need. The iPhone app that lets you change settings is $10 last i heard. Its an excellent app.
This is a little bit of an unusual question and to me, it makes me think you are trying to use the BMS for something it should not be used for.
Disconnecting the battery from your system is pretty tough on everything and should be avoided except to protect the battery (the purpose of the BMS).
What are you trying to do? Control charging? (always the job of the charge controller)
Control discharge amps? What is the use case for this?