The best afflict cards are definitely Wildfire Eternal and Neheb, the Eternal, as both force your opponent to make a decision when blocking that could result in a worse outcome for them in the long run
These are not necessarily stronger than other rarities (although they can be) when it comes to the card game, but they are harder to come by when opening packs
They can only take one or two hits each and aren't very good for attacking (or 'Challenging') your opponent's cards, but they cost a mere one Ink to deploy, meaning you can drop them on turn one
No, no you dont
As with the previous ones, I've had no issues of cards falling out and this one is great for holding cards from the Azurite Sea set
Izzet (blue/red) decks are not known for the ability to ramp, so you'll be spending the first few turns setting up mana rocks for mana generation, leaving your defenses open