In my opinion goblin is the best choice for race, at least speaking from a destro/aff perspective, atm the jump is soo good vs all the fotm nelf rogues
If you don't care much about survival, belf is best for pure dmg with blood thistle, orc tops belf for premades tho
Atm destro is the goto spec if you want kills, demo for control and aff for support/spread dmg
And then u got the choices wether to gear for the 9.99% haste for an extra tick on immolate, as aff you want to stack haste all the way
Demo I know nothing about, so can't give much constructive criticism on that
Use imp! Auto dispels 10 sec CD,
Practise burst rotation if u plan on goin destro
Gl, hope you have as much fun with you lock(s) as I do