your twin list is a lot different than what I'm used to seeing.
See link for list.
http://mtgtop8.com/event?e=10980&f=MO
Creatures - Maindeck spellskite is okay, but I would run 1-2 tops... put the rest in the side. Umm... no snaps? If you're building budget you should say so... snaps are nearly required to be competitive. Grand abolisher is a weird choice... care to elaborate on it? Little jace, (Vryn's Prodigy) would be okay too. Delver can go... if you want to be a twin deck, otherwise load up on burn and get rid of the twin and play delver.
Instants - angel's grace/silence are two other weird choices... These cards in my experience are not very good. You need the 4th bolt a Cryptic command would be good. It's very versatile. Some number of electrolyze is necessary to make affinity bearable and the mirror match.
Artifacts? - scepter? your plan is to spam silence/grace over and over? Not a great plan overall... there's a couple reasons why.
1. Grixis will just doesn't care about that and will control you out of the game. It's very likely that fast decks like affinity will just kill you before you get combo online.
2. silence and grace only stall for a turn, there are plenty of decks that can just kill you the next turn while dealing with combo at the same time.
Mana - scalding tarns are the better fetch if you have them... over mesa's I would think... You need a handful of basics or you'll lose to an opposing blood moon. Also a desolate light house is nice it lets you filter your deck.
Sideboard - swiftspear? get rid of that. dispel is fine, run at least one maindeck though. Disperse is bad cut it. So is render silent. You need a stony silence or 2. Keranos is nice for the grindier matchups. Manaleak is okay, but in the matches where you need it negate costs the same and is just a hard counter for opposing spells that matter in those matchups. Run a couple blood moon/magus of the moon if you can after you work on your manabase some, it hoses tron and bloom titan pretty hard. Otherwise side a couple ghost quarter or something.
You need a solid plan for the following decks.
Affinity, Grixis, twin, zoo, jund, tron, bloom titan ... have you done any testing?