In what realm i should play

Hello im about to start playing can u tell me
Lordaeron ot deathwing ... i heard that deathwing is bugged server and
Lordaeron is better .. also Im Bulgarian any Bulgarians out there .. now i got rogue 40 lv in deathwing can i transfer it to
Lordaeron or i must start over , and in i can how is transfering done ? and why is
Lordaeron best LOTH server ? and i never played higher than TBC ( im old school player) can u tell me thats new in cataclysm and LOTH or Cataclysm ?