The only way to maximize Fasting's effect is to combine it with cards or board states where you have no cards in your library. The only card I think goes well with Fasting is Leveler, which no deck in legacy currently uses.
Because their main colours are red and green, color slots for other better supported tribes. Goblins are just way faster and end the game by turn three, not to mention goblin matron acts as a tutor (among many other goblin-esk card advantages that are fairly superior to what shamans have). Green has elves that reliably combo out just as fast as goblins can dish out game winning attack steps.
Basically any aggro strategy from shaman builds will be completely outclassed by goblin decks. The same is true for combo builds being outclassed by elf decks.
You can try to add burning wish to the deck to either combo off when you need too or to pull out protection pieces from your side board.
I would remove the abyss in favour of something else, maybe Goblin wielder to bring back your memory Jar?
I would add some hymn to tourachs, I have a similar decks and they work wonders against control. If you want to spice things up you can always consider fervent charge.
You can try Terravore, it can grow pretty big once you have a stuffed graveyard. Mesmeric Orb can help act as a secondary grisly salvage that also mills out your opponent.
I would get rid of the telepathy's and add in some Sulfuric Vortex's since this type of deck is typically weak to lifegain effects. You also don't have anything that would benefit from using telepathy anyways.
Add 2-3 more lands, 22 is a little low if you want to be casting big dragons. Remove the dragon whelps, goblins and tome scour. Try to add more ponders. Your deck description seems to propose a control deck, you want to have around 8 counter effects like counterflux and 8 draw spells minimum.
Control decks typically stall the game until you can get your trump card or "win condition" out, in this case your dragons should be one of the last cards you play and by that time you should win the game shortly after. I hope this helps.
Basically any aggro strategy from shaman builds will be completely outclassed by goblin decks. The same is true for combo builds being outclassed by elf decks.
I would remove the abyss in favour of something else, maybe Goblin wielder to bring back your memory Jar?
- said by no one ever...
Control decks typically stall the game until you can get your trump card or "win condition" out, in this case your dragons should be one of the last cards you play and by that time you should win the game shortly after. I hope this helps.
Moved to Casual -Cythare