1. can i do comparable ( to subtlety ) damage as assasination rogue? what is difference in %?
2. shadowcraft shows me that subterfuge is 25k dps more than nightstalker, is it real?
3. simcraft shows me, that my dps now as assasination is 25-30k less than subtlety ( 55 and 59 artifact level ), will it be the same gap when i get 59 assa artifact, or subtlety damage is always higher?

Hopefully an easy question. I have always just gone for the top trait relics but now i have a non top relic and need to understand the comparison chart. Does the Weapon iLvl column # the number that should be added to the +50 Item levels for example? is a say +51 item level with Jaws of Thunder the same value (60) as  a +60 item level Furious swipes  or do i add the Trait bonus so to speak to the ~900 item level? Thanks you for the clarification.
 
https://www.icy-veins.com/wow/beast-mastery-hunter-pve-dps-artifact-talents-traits-relics 

Hey guys and gals. I'm fairly new to assassination, my rogue was originally a SUB rogue, for legion I changed to Outlaw, and finally Assassination. I've been raiding now with it for a good couple of months with my current spec, I've tried to follow the icy veins guide as close as I can, when it comes to BIS, rotation, etc.  I'm struggling to get the numbers, I'm supposed to be getting according to my gear level. 
http://us.battle.net/wow/en/character/fizzcrank/Atreyiu/simple
I am aware I don't have all my BIS, but I'm working on it. My guild is currently doing NH Heroic, and so far we are 6 bosses in. And most of the pieces I need are in the later bosses, so far we haven't been able to progress that far.
according to warcraftlogs, my dps is in the very low end of the spectrum. and I agree, there is another rogue in my guild that puts out almost 35% more dps than I do, and he is at 898 right now.
these are my logs
https://www.warcraftlogs.com/rankings/character/22393791/latest/
 
these are the logs for my guildee, that whoops my butt in dps every time (he is a really cool dude and has tried to help me, but because of his and my work schedule I only get to talk to him during raid times)
https://www.warcraftlogs.com/rankings/character/17154275/latest/
 
Also my rotation for single target goes as follows: Garrote-mutilate-rupture(5point)--mutilate-mutilate(5point)-envenom-kingsbane--vendetta--garrote(keeping it up)-mutilate-mutilate-vanish-rupture---rinse and repeat.
 
So if you guys have any advice, on areas I could improve. I would greatly appreciate it.
 

Ok so let me start out by saying my weapon is lvl 885(fire artifact) and has the following relics equipped: 

Fires of Heaven 855 +10% Pyro (Fire)
Raven's sight 865 +20% FS (Arcane)
Fires of Heaven 845 +10% Pyro (Fire)
(I know it doesnt add 10% each)

i have in my bag i have:

Seawitch's Foci 840 +12% Ignite (Arcane)
Sizziling Fang 875 +12% Ignite (Fire)
Soulforge Ember 835+12% Ignite (Fire)
Molten Giant's Eye 860+3% Fire crit (Fire)
Fires of Heaven 840 +10% Pyro (Fire)

Ok last time i took out an Ignite relic i lost 40-50k dps. I put in the 855 Fires of Heaven relic and just did not stack up even though it was a 10ilvl increase. So my question is should i go tripple Ignite? or maybe double ignite with the crit relic too. I care a lot more about mythic + dps more than raid so keep that in mind. it doesnt seem like the pyro one is very good compared to ignite. Also if anyone can offer an explanation as to why i lost so much dps by switching in the supposedly best relic (pyro) that would be great. My best guess is that i was on some kind of soft cap with mastery and that it did a lot more dps but idk

I think the best two options are running three ignite for insane cleave damage in mythic plus or, Sizziling Flame, Molten Giant, and Seawitch.

Here on Icy Vein's under the Arms Warrior DPS guide here is the recommended relic choice. I was under the impression that [Exploit the Weakness] was our top priority even if it meant 20-25iLvl difference. Since it would increase the proc chance by a factor of x2 with all three relics increasing Tacticians...
Why does this guide on Icy Veins say otherwise? Is it because the information is out of date and hasn't been updated?
 
(Original Link: https://www.icy-veins.com/wow/arms-warrior-pve-dps-artifact-talents-traits-relics)

 
Unfortunately this is not someting I can just run a Sim on because I don't currently have any [Exploit the Weakness] relics.