DPS mod is more important at the lower end of the diminishing returns curve. The problem with that question is availability- % crit from buffs is very limited and can only be upgraded roughly 2% at a time while DPS mod is available on all sorts of items and adornments.
DPS mod is a direct percentage increase in autoattack damage. AGI/WIS spec has nothing to do with it, the fact that DPS mod is a permanent upgrade while crit chances are variable and difficult to improve makes mod the more powerful increase to your damage over time.
Also if ya use /weapon in game you will see your proc %'s...slower the weapon the more chance ya have to proc...I think it works the same with crits. If ya want to see what crit %'s can do for you try using the crit potions so atleast you can get an idea of what crits can do for ya. I've swapped out my neckpieces several times...one has the DPS mod of 25 with BoE V which gives 25 extra to my spell dmg vs. my MOA neck piece with 2% ranged and melle crit and it about evens itself out.
is hard to give a simple comment on that cause it ofc depends on what other gear you are using and what group you are in usually.
e.g. if you always group with coerc/inq/dirge you pretty good on dps already .....
You got the ears right and also the bracelett. If you don't have a dirge or temp I would even say ditch the planar orb and use the Relic Hunter's Solitaire. I personally think + to crit is almost always better than a dps mod. In raids I never find myself needing more dps mods and after I burn my shorts I often find myself at or over the cap.
If you really want to go nuts on crit gear you could change your hat out for
\aITEM -600871799 545832289:Cryptstalker Helm\/a
dunno if you have access to PHH loot but maybe if it were going to rot this is a better choice
\aITEM 848747828 -626429481:Praetorian Hood\/a
You are wearing the Piecemean Flesh chest but a better alternative is this which has 2% to crit
\aITEM -863538159 1893182919:The Dhampyre's Linksteel\/a
And if you feel like wearing leather chaps you can always get the ones from Viswim that have 1% on them
\aITEM 729371174 1142049968:Viswin's Hunting Chaps\/a
Those are most of the decent crit items I know. Theres a few more when you start going into EH and contested loot but I assume if you are doing those than you know about them already.