Why would 100% crit chance leave your attack and attack% bonus quite low? Do you mean because of material slot limits in gear? There are other ways to boost Attack%.
But in essence, I agree with you. It's not necessary to push to 100% crit chance. The tipping point seems to be around 50% crit chance. After that point, if you have to trade off between Attack% and Crit Dam%, mat for mat, prioritize Crit Dam%.
From the damage formula, it's clear why.
final_damage = (base_damage * rand(0.95 to 1.05) - armor * (1 - armor_penetration))
* (ability_multiplier)
* (1 + critical_damage_bonus + flanking_bonus)
* (1 + attack_bonus + damage_multiplier + type_bonus)
* (1 - magic_resistance)
Simplified: final_damage = (1 + (crit_chance * crit_damage)) * (1 + attack_bonus)
Now from just that equation, you'd think that it is always advantageous to boost attack% first, since it multiplies into everything else. BUT, it turns out that it is much more expensive, in terms of the crafting and accessories economy, to buff Attack% by 1 than it is to buff crit_damage_bonus by 1. It's hard to get an Attack% over 50%, but it is relatively easy to get a Crit Damage% over 50%, since you start with 40% default! In fact, you can get it up to 200% without too much effort.
Mat for mat and slot for slot, once you get over the tipping point of about 50% crit chance, you are better off allocating those slots to mats that give you +2% or more of crit damage than for a mat that only gives you +1% Attack%.
This is not to say that you shouldn't continue to invest in crit chance. There are other benefits, like Flow of Battle, where more critical hits means higher effective DPS. So when you can, boost that crit chance% also. For example, if you get to 58% or over, a 1.75% Dex/crit damage mat, like a Great Bear Skin Rug mat in a Utility slot, has an edge over a 1% Attack mat, all else being equal. Too bad you are not a rogue, or else you'd get the additional benefit of Attack% from Dex via Great Bear Skin.
And since Attack% comes from metal mats and Dex/Crit Dam% comes from leather mats (with one exception), you should choose gear that has leather Utility and Offense slots. Then, if you have no other choices, go for Metal Utility (Strength) and Offense slots.
This is why schems like the Superior Prowler Armor (9 Leather Utility slots) + Snoufleur skin (to remove the class restriction) and for 2H, the Warhammer (12 Leather Offense slots) are so popular. As a 2H, you'll find most of the weapons have Metal slots, but that's fine. You can find hafts and grips that give more leather slots. The Bound Two-Handed haft has 9 leather Offense slots.
Spend some time here
http://dragonage.wik...apon_schematics and here
http://dragonage.wik...rmor_schematics and good luck!
*The one exception is Avvar Cotton, which gives 1.75 Dex in Cloth Utility slots.