There are around 60 cards in Magic in blue, red, and white that have convoke, giving you a healthy selection of cards to pick from to fill out your deck
The Anathemancer deals 2 damage to the Grazer, while the Grazer deals 0 damage to the Anathemancer
Thats how much
This may sound like an issue of pay to win, and to a certain extent it is, but from what we were shown in the demo it seems like its not too difficult to assemble a competitive deck using just the resources provided, meaning winning will ultimately come down to the skill you have more so than the cards you own
1012 lifegain sources lean incremental/repeatable (Soul Warden effects, lifelink, upkeep gainers)
The evolved Pokemon maintains the same amount of damage it had prior, but it is cured of special conditions