You need Impale!
Imaple is a must in pvp
I think you could consider some more end redux especially in attacks unless you'll be teaming with someone who can keep your end topped up all the time. You've got those slotted like a regen might - but you dont have the stamina. 
To me this looks like a unplayable build until the 30s. As you won't be able to scrap until level 26!
Spine Regen is a very expensive build. Spine's single target chain is very cheap ( Lunge, Impale, Lunge, Ripper ) but the AoEs suck endurance. My Spines/Regen runs out of endurance with 2 recharge and Hasten so I had to put some end reds in some attacks.
Impale is a must in PvE at level 8. You are you scrapper which means you need attacks. Barb Swipe is rubbish, Spine Burst is expensive, so you need Impale for your single target attacks. With Hasten lunge , impale , lunge works as a nice half attack chain when Hasten is up. When you get to level 26 Ripper fills in the gap.
IMO Murky Cloud is unnecessary until you have the end to run it ( post stamina ).
Slot Dark Regen with end reducers. At least 2. The heal is unnecessary as it gets you to full with 3 enemies anyway.
The damage auras... getting 2 damage auras and then only slotting one damage in them seems... strange. Only put one ACC in there.
Lunge should probably be 6 slotted in early levels and then respecced down to 3 or 4 slots.
I would 6 slot Spine Burst and Throw Spines but only put 1 ACC in each.
@Unthing ... Mostly on Union.
So I'm planning on making a spines/DA, mostly PVE but casual PVP once I get past 40 (hence last 3 powers are purely there for PVP), and I'm completely clueless as to how a spines build should look.
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Exported from Ver: 1.7.6.0 of the CoH_CoV Character Builder
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Name: Eon8
Level: 50
Archetype: Scrapper
Primary: Spines
Secondary: Dark Armor
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01) --> Lunge==> Acc(1)Acc(3)Dmg(3)Dmg(42)Dmg(43)Rechg(50)
01) --> Dark Embrace==> DmgRes(1)DmgRes(5)DmgRes(5)EndRdx(7)
02) --> Spine Burst==> Acc(2)Acc(7)Dmg(9)Dmg(9)Dmg(11)Rechg(50)
04) --> Murky Cloud==> DmgRes(4)DmgRes(11)DmgRes(13)EndRdx(13)
06) --> Build Up==> Rechg(6)Rechg(15)Rechg(15)
08) --> Hasten==> Rechg(8)Rechg(17)Rechg(17)
10) --> Obsidian Shield==> DmgRes(10)DmgRes(19)DmgRes(19)EndRdx(21)
12) --> Combat Jumping==> Jump(12)
14) --> Super Jump==> Jump(14)
16) --> Dark Regeneration==> Acc(16)Acc(21)Rechg(25)Rechg(25)Rechg(27)Heal(46)
18) --> Swift==> Run(18)
20) --> Health==> Heal(20)Heal(27)Heal(40)
22) --> Stamina==> EndMod(22)EndMod(23)EndMod(23)
24) --> Acrobatics==> EndRdx(24)
26) --> Ripper==> Acc(26)Acc(29)Dmg(29)Dmg(31)Dmg(31)Rechg(43)
28) --> Death Shroud==> Acc(28)Acc(31)EndRdx(33)EndRdx(33)EndRdx(33)Dmg(40)
30) --> Quills==> Acc(30)Acc(34)EndRdx(34)EndRdx(34)EndRdx(36)Dmg(40)
32) --> Throw Spines==> Acc(36)Dmg(36)Dmg(37)Dmg(37)Rechg(43)
35) --> Oppressive Gloom==> Acc(35)Acc(37)Dmg(39)DisDur(39)DisDur(39)
38) --> Stimulant==> Rechg(38)
41) --> Conserve Power==> Rechg(41)Rechg(42)Rechg(42)
44) --> Focused Accuracy==> TH_Buf(44)TH_Buf(45)TH_Buf(45)EndRdx(45)EndRdx(46)EndRdx(46)
47) --> Aid Self==> Heal(47)Heal(48)Heal(48)IntRdx(48)IntRdx(50)
49) --> Cloak Of Darkness==> EndRdx(49)
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01) --> Power Slide==> Empty(1)
01) --> Sprint==> Empty(1)
01) --> Brawl==> Empty(1)
01) --> Critical Hit==> Empty(1)
02) --> Rest==> Empty(2)
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I've gone for SJ to cover up the glaring KB weakness, and add enough hold resist to stop blapper holds being an issue. Decided against impale on the lines of saving endurance by mass AoE killing, not wasting attacks on single targets (hence 2 damage auras). Biggest problem is I don't have a clue what the end is like, or whether I really shouldn't be ignoring impale. Any tips?