Firstly, I'd like to point you to my take on a similar concept:community.wizards.com/go/thread/view/758...
Looking at your deck, I'm interested in how this really is a 'flicker' since between Cloudshift
and Restoration Angel
you only have 6 'flickers' and 16 creatures with ETB effects.
So some things that I've picked up and had discussion about in general: Righteous Blow
I've found underwhelming, maybe a meta issue but unless you're getting it early there's not much value in it. Thragtusk
and the Angel are good enough blockers later. It's very rare that you'll want to top deck a Righteous Blow after turn 4/5.
is a sideboard card for me. You'd probably get more joy out of Stonehorn Dignitary
or Fiend Hunter
I like Evolving Wilds
as it helps me thin my deck and since you're playing green Rampant Growth
is nice option for Ramp and thinning your deck. You have several high mana-costing creatures so the ramp is quiet useful.
Next, Thragtusk and Acidic Slime
these are 5 CMC creatures. You don't really want to be seeing these too early on since you have to wait to cast. I would drop to 3 of each so that you have a good chance of drawing one a game but not ending up with a hand full of creatures waiting for you to get mana out. Roaring Primadox
could work well in this deck to help you flicker.
Another card I'm not sure of, but you can see how you feel is Garruk's Packleader
, this gives you additional card draw everytime you flick a Thragtusk or play your Angel. This is a 2-of card, you don't necessarily need it every game.
Lastly, Phyrexian Metamorph
would work in this deck since it allows you to copy an effect that's on your board and you may be able to cast without paying the life with the Birds, but even without its ok because of the Phyrexian mana cost.