No. Samsung Metro XL is made of high quality Polycarbonate material.
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.
Yes, you will get a pair of headphones in the box as standard accessories.
Yes, Samsung Metro XL does support the Tamil language.
Yes, Samsung Metro XL does have call conference facility.