Yes, but you have to use sim card adapters to make them work.
Samsung B310 comes with 800 mAh battery. But it is very efficient. You do not require to charge the phone for almost 3 days with moderate usage.
Yes, Samsung Guru Music 2 has speed dial function.
No. you can use whatsapp in this phone.
No. Call recording option is not available in Samsung Guru Music 2.