Did you skip a bunch of stuff in Broken Valley? Aside from your level I don't see anything wrong with your stats or skills.

When you get up another level Explosive Arrows will help with groups (and you can also learn level 1 of the Healing spell).

I always used Increased Damage enchantments first in bows, then Increased Magical Damage and then Butcher.

Derk the smith in the Broken Valley village sells a bow a little better than you have. Alternately, you can get one as a quest reward saving someone from a troll. From Lancet's DKS Guide, D2:ED bow section:
----------------
Ranger's Rest
----------------
OBTAINED: Purchased from Derk in Broken Valley Village.

Bow L10 (2031 gold)
Ranged damage: 4 - 40; Magic damage: 6 - 10; Critical Chance: 7%
+2 to Heightened Reflexes
+2 to Ranged Damage
1 empty charm slot
1 filled enchantment slot - Increased Magical Damage 4
"Traveling in the wilds is dangerous business, but with a bow like this in
hand, rangers can rest assured they are well armed."

----------------
Rothman's Bow
----------------
OBTAINED: Head southwest of the South Valley Shrine and you'll see a large pit
covered with twigs. Go near, and a man will ask for help. Rescuing him
requires a Rope (found in many places). Once rescued, a troll will attack the
both of you. Kill the troll, and the man gives this bow in thanks for his
rescue.

Bow L12 (random)
Ranged damage: 8 - 25; Magic damage: 7 - 22; Critical Chance: 10%
+1 to Wisdom skill
2 random buffs:
-Hitpoints: +15-22
-Dexterity: +2-3
-Ranged Damage: +2-3
-Heightened Reflexes: +2
-Critical Chance: +2
1 filled enchantment slot (random)

Did you check merchants each level, either for equipment upgrades, or anything with a higher level enchantment you could remove to get the formula?

I had Lockpick at level 4 going through Maxos temple, IIRC, and hung on to Jagon's necklace for that skill bonus (maxing the skill eventually and turning the quest in). If you are keeping track of chests you couldn't open, you may want to go back for them before taking over the battle tower.

If you wish you can teleport back to Broken Valley and then head to the fjords. You may need to do a little jumping backwards to avoid melee combat (or not, depending on how well your two hander does), but the opponents there are fairly spread out, relatively easy for a ranger to defeat (I entered the fjords at level 13), and give lots of experience points. Save periodically, though, as a miss-jump on the mountain path could have you falling of the edge, and having to deal with a few opponents on the way back up (Hide in Shadows could help with that, though).