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 can change the fonts size in Samsung Metro XL.
No. This phone do not have wireless FM.
Yes, you can adjust brightness levels as per your rquirements.
Yes, Samsung Metro XL does have Bluetooth.