Samsung Metro XL does have 128 MB internal memory.
You can set up to 10-speed dials in Samsung Metro XL.
Yes, you can play youtube videos on this phone.
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, Samsung Metro XL does have Bluetooth.