Looking for serious constructive criticism, but I fully expect some flames and sophomoric responses as well

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Background:
A. I play in no-CP cyrodiil and BG's. So throw CP specs out the window.
B. I run 2H/Bow with Willow's Path and Bone Pirate for sustain. 1.3 mag recovery / 2.4 stam recovery and 20K/10K/30K stats on health/mag/stam respectively
C. I run your standard 2H bar - executioner, surprise attack, ambush, mass hysteria, rally : incap
D. I run a somewhat standard bow bar - poison inject, vigor, relentless focus, shadow disguise, Flex [my flex is either pierce mark, shuffle, shadow image, or rapids depending on situation. core is shuffle though for the most part]
E. I run your standard nirnhoned 2H with poison/disease enchant and Bow is infused weapon damage
D. I run almost exclusively solo. Most of my issues below are 1v1's. I'm looking on how to deal with classes.
My Issues:
1.
Shadow Image - This ability is raved by the "pros" and I frankly find it terrible. First, I have to have a target to use it. If acting reactively, it is extremely hard for me to get the shade up while trying to dodge-roll/vigor cloak into heals with target at back. But more imporantly, even if i get the shade up.. it's a 28 meter range. 28 METERS> this is beyond awful except for the most niche of spaces. I can't tell you how many times the shade is either out of range, LOS'd, or the cooldown at 20 seconds has already passed by the time I hope to use it. If I use proactive before engage, I find it always is out of range or de-summoned by the time I need it. I just frankly suck balls with this skill.
2.
Being Marked - I find myself routinely being hunted in cyrodiil by a pack of nightblades. They will run together in 2 to 4 man groups and they notoriously place piercing mark on me. Mark plus multiple nightblades is just insta death for me. And slotting purge for this outcome seems very niche/impossible as that flex spot is usually shuffle for me. 1v1 against nb i feel ok. even 2v1 it is possible but unlikely. But marked with multiple just seems impossible.
3.
Stam DK - I read how this class is a joke. I guess i'm a bigger joke then. Because when i engage stam DK 1v1 this is how fight goes. Volatile armor return my range, venomous claw/noxious breath at short range with light attack weave. Wait for take flight and boom - executioner / good night Vienna. Oh - and throw in some 4K heroic slashes for good measure. Meanwhile my damage hits for paltry sums of 2 to 3K and is easily healed through / negated. Mass hysteria into an incap, sure that does soften them up pretty good... but never into kill range. never.
4.
Templars - Usually soften them up pretty good on the open. Then they reset fight to full heals.. stand in their own heal pit. Proceed to purifying light my face while destroying me with perma snaring jabs or puncture sweeps. eventually ended with DBoS while being javelined. Again, mass hysteria into incap does some good things in this fight but they are so damn tanky they just heal through it.
5.
Sorcs (the no pet kind. I believe they are stam). A good sorc is running 21 to 22K health with another 8K in shields. My open does little except take care of the shield and maybe another 5K of health. They dance around, blink here and there... avoid and patiently wait. When ready - CC into curse / crystal frags. Good night Vienna.
6.
Magblade - lol, this one isn't even close. fortunately i almost never see them. but when i do - wow. It's not even a contest. They shake off any upfront damage I do and proceed to just light attack/swallow soul weave my face. leeching as they go in and out of stealth. eventually incap and mad burst --- good night Vienna. Some will lay a path down and just sit in it while doing the weave strat I noted above. their sustain and leech heals... wow. hits as hard as i do but heals them.
7.
Mag DK - almost never see this. i guess i'm just looking for advice on this one in case i do. i know these are the flame whip boy bands... but again - i just never really see them.
I find my most success is against wardens and other nightblades. I feel comfortable fighting them. DK's and Templars are just ridiculous sustain and mitigation. Easily resetting fight and then wearing me down. Sorcs are usually ok but the high end ones that know what they are doing... I feel like I have little to no chance.
Thanks for any and all advice. New to the game and looking to improve.