Normally I see bow ice type use a frozen set to maximize it.
I like your mythic choices.
Crystal affix that I would recommend
Dodge
Crit damage.
Crit chance if you won’t rely on coat proc / vial
Attack Speed
2x Deadly strike if you want to maximize crit dmg or block if you want added avoidance
Sets that I would recommend.
Permafrost
Frozen
Momentum - You need to invest I guess at least 2 movement speed legend and I guess 20 dexterity.
Adventurer - For PVE the movement and damage is pretty nice the condition is getting gold.
Defiant I guess if you like the 25% damage / reduction.
I don’t use proc builds but this sets gives dmg on them.
If you want to maximize dmg of procs you can use maelstrom set affix. (This can only be attained via legend item drop)
You can also check out identity set affix if your main dmg is skills from other classes like some of your cata ring
If you plan to use your eternal cataclysm you can craft a nadroji amulet that has +2 set legend affix then add a elixer to maximize +4 set affix.
Legend affix that I think would benefit a dmg build.
Glasscanon it lessens your HP but high floors normally kill a user with one chance hence the avoidance
Legend ED% dmg on your armor but you need to recraft though due to it’s only found on nadroji armor.
Multi attack
For going to high floors you would need some form of avoidance.
Sanctuary is nice for it.
A crystal dodge affix wouldn’t hurt.
Crystal block wouldn’t hurt if via crafting you can only get in via your OH.
I normally put dmg affixes on my mainhand to maximize dmg and put supporting affixes on gear.
If you can maximize your eternal bow on the build then use it but if you want flexibility then craft a bow.
This is only my suggestion and you don’t need to follow it. Sorry that it’s long and I guess you need more resources on what I posted. >.>
Procs at DQ are Procs per second not per attack.
Guides that uses bow.