Bow combat has 3 skills. Magnum, Crash, and Mirage. Mirage is barely viable because it doesn't get much damage increase over ranks - the 'shock' damage is VERY slow to rise, and not influenced by your weapon or dex, so it's always very small. It's only real use is slow killing, where you want to conserve arrows, or against liches.
Crash will MURDER whole rooms, but is ineffective against single enemies. It also has a fairly high cost to use, in terms of SP and MP, and if you don't trigger the splash damage just right then it totally fails.
Magnum is the REAL ranged skill. Especially since the change from charge-up to cool-down it's possible to magnum spam, which is highly effective. The problem is the terribly long aim time and the miss chance. Most of the time, by the time I'm able to get a shot off, the melee monkies have already done a Smash and knocked the enemy out of range. Then it's impossible to follow through with anything. The damage output isn't as high as melee either, though it's close enough that it still works.
What the game REALLY needs, I think, is a large nerf to melee damage, and some skill or buff for archers to be able to aim faster or use luck to turn a missed shot into a hit. It's just absurd when regular attacks can get over 1k damage, without trans or crit or smash, while a high-ranked critical magnum scores about 1,500.
As for new archery skills, I'd like to see some sort of 'pinning shot' where a magnum shot hits hard enough to impale the enemy to the ground, various poisons like sleep, slowness, or enraging, and some sort of skill that would help to shake aggro or raise defense... Being able to burn MP to charge arrows with elemental damage would also be sublime. One thing I'd REALLY love to see, would be Greatbows. Massive things that need to be braced on the ground to fire spear-sized bolts of raw power, turning archers into balistae.