How can we make the focus mechanics more interesting?

Here are a few ways I would spice up the focus mechanic. Listed in order of development work required (least to most)

1) Passive Stance: Increases focus regen, but reduces spell damage by X%. Rather than its current (Increases focus regen at the expense of damage resistance, attack speed and movement speed. Fizzle chance is greatly increased while in this stance)

2) Aggressive Stance: Increases spell damage, but increases the focus cost by X% (can't work with offhand attack since it has no focus cost)

3) Give lunar a new active skill Umbra Arrow: Ranged shadow attack that grants Lunar Stillness (increases focus regen for 10 secs) and gains bonus range at night. This skill would need low damage like ice arrow so spamming it is not optimal.

4) Active skill that does increased damage based on how depleted your focus pool is.

5)Active skill that does increased damage based on how depleted the targets focus pool is.

6)Active skill that siphons focus.

What are your ideas?