Oona's Blackguard will make all the Rogues a bit bigger, but the discard ability is great when you have a lot of creatures on the table. Play a Marsh Flitter and you will have three 2/2 creatures with a discard ability and one of them also has flying.
To make the deck a little bit faster, Frogtosser Banneret is doing a good job. But best of all this card also reduces the Prowl costs! Now a Stinkdrinker Bandit can be cast for 1 mana Prowl cost instead of the normal 4 mana casting cost.
Put a Deathcult Rogue or Inkfathom Infiltrator beside this card and you will do 5 damage with a unblock able creature + the opponent has to discard a card. Imagine when you have more than one [[Stinkdrinker Bandit] on table.
Notorious Throng can be a killer card in a multiplayer game. If one player is getting weak, you just launch a full attack on him with all your creatures. Then you will get loads of flying creatures and with the extra turn, you might be able to finish off another opponent . With a Oona's Blackguard and Stinkdrinker Bandit on table this will be a bunch of killer flying creatures + you will skip the summoning sickness because of the extra turn. you might catch your opponent by surprise.
For the good fun, I put in the card Knowledge Exploitation. With a reduced Prowl cost this card can give some good fun for just 3 mana. For example, if you are on the losing side, how fun would it be to play a Wrath of God out of your opponents library.
When you replace some of the cards in this deck with some more expensive rares, I am sure this deck can become very good.