What skill is sill usable for pathfinder ?

Hi,

I was just wondering if someone know what skill are still usable.
Right now i use gas arrow explosion pathfinder and need up to 1.2 time my mana bar (around 600 mana but unlimited mana flasks) with one beast of bow for my level to kill one add.

Poison is a turbo joke (adds are cleaned super fast but rare/unique take years) and most of the bow skill are turbo trash now.

So if someone has a lead, thank you in advance.