I got the original text document for this build from Moth Priest. Expect to see me update this with a lot of classes in the very near future.

I see you've implemented some of the advised changes, so expect a +1 from me when I'm done writing it.  Particularly skills, the newer version is a lot closer to Half Assassin/Mage than the original.  Lack of focus is probably too much content for a short blurb on one of many Bare Bones Builds anyway, so at most it would warrant a short mention. 

It's not so much about any particular Minor Skill, the deadliest nerf comes from working too many peripheral skills at the expense of the Core ones.  If you just Backstab, then you don't do enough strikes to unlock more Armsman perks, so I generally advise people to do some fighting early on to keep 1H ahead of the pack, and neglect Destruction (Which is classic, but not very Stealth, so I usually drop it entirely.) Alteration, and/Restoration to avoid going up another NPC tier before your Damage is up there.

Cut down the Build Info: section some, especially deleting information that is repeated in later sections.  Also, you dwell to much on the Racial section, especially for 1 Race to the exclusion of others.  All good points, mind you, but not all of them apply to Nightblades in particular.  Either trim out a lot of fat, or mention other Races (Dunmer are pretty much Born Nightblades) to warrant the large paragraph.

Restoration isn't actually all that useful for Nightblades, so I'd cut it for simplicity, and Focus.  Also "Alteration and/or Light Armor" might be a good edit, since they hardly need both, but either add good things to the class (Wind Walker, and ParalysisDetect Life in particular.)

The problem with cutting down the build info section is that it's really the only thing that keeps this from being a list of choices and their rationalizations. I might cut down on the race section though. Good point on the Light Armor thing, I'll add that in. I find Restoration to be useful for Nightblades. Being able to heal mid-combat is great, and Recovery is nice when you're using every school of magic that uses Magicka except Conjuration, not mention the possibilities with Necromage should the player become a vampire.

I suggested it, because it reads as a list of choices, and rationalizations, rather than a description of what the Nightblade actually is, and does.  At least move the Player mechanics down to the appropriate sections.  

Restoration is nice, but hardly necessary.  I know about the Necromage/Vampire glitches, but you didn't mention them, and it tends to pigionhole this build more than it needs to be, and basically requires a Dunmer (Now your second choice) to counter being Weak against Fire.  Not to mention, you have to basically double the particulars of the build to build around them, or the weaknesses (Like Sunlight) outweigh the advantages.

Not to mention the fact that this isn't a Nightblade build, but one of many, so "Bevity is...Wit."

I agree that Restoration isn't necessary, but it certainly complements the build nicely, and in TES games past has been traditionally included in the Nightblade's skillset. I can also tell you from experience that being a vampire does not require being a Dunmer to play effectively. Nightblades are effective vampires because the skills that benefit from vampirisim the most (Illusion and Sneak, as well as Restoration with the Necromage glitch) are also found in a Nightblade's skillset, making it a natural choice. I mentioned the Necromage/Vampire glitch in the build itself, check the last sentence of the build info section.

KISS, you have a lot to go through, though I like what you did with the other Classes, and don't see any glaring need for improvements.  Generally, I wouldn't personalize them as much, and focus more on the Classic lore based builds, but that's me.  Also, I liked the Italicized text in the introductory sections, they add a bit of visual appeal that I found subtly fetching.

I'll warn you to expect a lot of argument about what actually constitutes a Battlemage when you get to it, but I look foreward to helping you with it.  For me, I thing 2H, Medium Armor (Heavy with Robes for Magicka Assistance, Protection, and access to magic items like Dragon priest Masks) and Destruction as Core Skills/Equipment with virtually any other Magic, and Warcrafting (Smithy/Enchanting) as options

No Pickpocket?  You specified Thief, not Assassin (I see them more as Assassins) so with that in mind, I'd add more Thief Skills.

The way I did the Nightblade was more of a combination of their Oblivion and Morrowind versions, hence things such as why Destruction is in there but no Lockpicking. I'm also trying to keep the number of skills used at a constant number across all classes (much like how in TES games past you'd only have a set number of skills per class). In general, these classes are more influenced by classes as they appear in later games than they do in earlier ones.

In theory, I have a lot to go through, but most of the classes so far are simply what Moth Priest had posted previously combined with edits from me. As far as the Battlemage goes, based on what Moth Priest had before, you're going to be set up for disappointment.