No. You cannot use Tata Indicom CDMA network sim card in this phone.
Yes, you can use the LED Flash as torch also.
Yes, Samsung Metro XL is a dual sim mobile phone.
Yes, you can connect Metro XL with Bluetooth headset.
You can store up to 1000 contacts in Metro XL. In addition, you can store up to 250 contacts in each of your sim card. So, if you are using 2 sim cards, in total you can store up to 1500 contacts.