I'd say curse is a pretty nasty status, except that pretty much only one weapon can inflict it. Granted you can just run away and cure on the health pads in base, but it knocks you out of the fight pretty well for that period.
Shock is definitely the number one most annoying status, given that it's so easy to inflict over a broad area with a lightning capacitor (T2) or voltaic tempest (T3), and both does DoT and interrupts attacks and movement. I run a pair of redwood bracelets in my T2 loadouts for a reason.
I think freeze is a lot more annoying in T3 when people break out the SB, but in T2 it doesn't seem to be all that horrible, given that the freeze breaks as soon as an enemy hits you, allowing you to potentially escape.
Fire is somewhat annoying, but not generally a problem to deal with so long as you avoid burning to death.
Poison is meh, much like in the clockworks.
As for damage types, shadow has the highest potential to be devastating, given that virtually nobody runs shadow defence armour. It's unfortunately outclassed by piercing, despite the number of wolver-series armour users, because of how the pierce swords work [insert autotarget RAEG here]. Elemental pulls up the rear, but given how little defensive stats matter in LD, it's still very viable.
Worst in descending order?
Grammar aside, it sounds like you're saying "Rank the status and damage in pvp from most threatening to least"
But I'm not sure since a curse for a 2 or 3-slot person can be significantly worse than shock.
Also, pierce can be super deadly for a vog user, but elemental and shadow could be equally bad for someone in full azure armor.
So in a sense, it depends on your gear.