I've always liked this archetype, however it seems plagued by consistent unreliability against the top tier decks, whichever they may be at the moment (that is, any moment).
I think what's going on here is that you're in the middle between control and aggro, and you should pick a side.
A few cards that the old versions used to include are Masticore, Sinkhole, Flesh Reaver and Contagion - I suppose their inclusion would shift the concept to Suicide, but I swear the Reaver and good ole Masti have won me many a games. Reaver has a bit of surprise factor to it whenever it comes down, and you have to know how to use it properly (for example, your life loss triggers after it deals damage, so if it's 4-4 you can beat ftw). Contagion as well is heavily underplayed yet will kill most of the utility critters in this metagame and is free (well ok, as close to free as you can get).
Oh, and Negator absolutely, ABSOLUTELY needs to be in there.
Ritual -> Negator is too insane to pass up for a flying critter that maybe will cost less than 7 after what, turn 4? Very few decks nowadays even play direct damage. When this bad boy comes down it's make or break for most control decks.
I understand DConf and Thoughtseize need some space as well - to be honest i'm not sure if the first one belongs - yeah, extra draws, but it's kind of a tiny body, easily disruptible and you have cards like Tombstalker in there. I'd much rather run DT, VT, Necro, Bargain, Consultation, Will, maybe even Grim Tutor. Yeah, it's good synergy with the top, I just have a hard time imagining that you would have the time to use it when you don't have any countermagic. I mean, against you, threats will come down and stay since you can only make them discard. So you could take out all 8 and put in more threats or removal - the point i'm trying to make is that they only help each other out and not necessarily everything else.
4 Extirpate seem a bit many, I'd switch a few to proactive threats, or other types of defence. I can see with all the discard you run being pretty easy to get rid of pesky stuff but there is such thing as too much. You already have 12 discard spells, i used to run 4 duress and 4 hymn plus 4 hippy and never felt like they weren't discarding enough. Duress itself already picks out most of the stuff that bothers you (which is not too much to be honest, this deck plays on autopilot beautifully.)
The whole basics vs fetches is subjective - this deck needs 4, maybe 5 lands in play to function properly, any more can be useful but not necessary. If you have more in hand, they're great Masticore fodder
So, tl;dr - my suggestions would be
-2 Tombstalker
-2 Thoughtseize
-2 Extirpate
+4 Negator
+2 Masticore / Contagion (4 of each between MD and SB)
I understand Sinkholes can be tough to come by, but I would honestly consider including them. If you're gonna be aggressive you need to go for the throat turn 1. Play those Dark Rituals into some nasty, bothersome stuff

anyways, good luck, let us know it evolves