1. Silverlight inflicts great damages on demons.
2. The sword you mentioned is Darklight. It is members' only so you cannot obtain one.
3. Depends on which types of prayer. Your max hit will increase when you activate any prayers that boost strength.
4. Resting can speed up LifePoint restore rate but it is not significant like the above mentioned.
5. Take a boat from Al-kharid and make your way to the castle. Form or join a party to start!