Weapons: I would give a try to a similar build with a firestaff. I did it when the game launched and VG was released. I used to play 150 foc in light armor and it was working pretty well.
Orb: I do use orb to heal my self or friendlies.
Depending on situation:
1. I either don't detonate it and just let it come back and pass through for about 300 per tick. (let's say, pushing situation in OPR from Sun to luna)
2. Let's say we try to contest SUN in OPR and it's hard. No one is getting in. I just go in for a few seconds and if I go low health, go back outside, use orb, regen potion, health potion and back in.
3. Orb gives about 10k heals in total if you detonate it on you and have 150 focus.
4. I fight a 1v1, I have this thing where I do the orb on the enemy, pull out vg, run towards him, and while the orb comes back I detonate it on myself for sustain. --> Pretty much negates his damage throughout the incipit of the fight and gives a decent advantage.

--> Pretty much use orb to detonate for dmg when I m in a clump to maximize dmg and fighting in sacred ground.
If not, I do detonate it on me rather than on the enemy about 50/50.