1. empbreaking
2. giant whisper is best IMO for offensive, more defensive types will take either aliot or, if the server has a lot of champs, raydric.
3. GR works only against few types of attacks-Asura, Sacrifice, AD. These all are extremely powerful but have fixed neutral element. As armor card is usually used for marc/ED to protect against freeze and stone curse, most used and annoying statuses at WoE, you have to be careful and switch armors around fast.
4. no
5. BSB combo is a "maniac" type LK. Works well if there are no profs around, as you gotta use shield and onehand weapon to prevent getting dispelled, as you'll have to rely on soullink giving 1hand quicken to achieve good aspd for BB. Be careful about choice.
6. Aura Blade ignores def only for that additional damage given by this skill, not your whole damage.
7. Fun for defensive char. Stuff up with defensive gear, decent aspd and status equip, and do some mess. That's actually probably best way to play LK as he hardly has potential to deliver killing damage.
8. Definitely valk, you need every stat point you can get.