Hearthpwn

Will not get into all of them, many seem accurate but most strongly disagree with the following:

-Twilight Runner probably more like 4 stars, nearly any Druid deck that cares about minions will run this

-multiple spell damage/burn mage cards, since I believe this will be a vialble archetype because of all the card draw and synergy from earlier sets as well: Lab Partner easy 5, Cram Session 3-4 stars, agree with posts above which have already pointed this out

-Frazzled Freshman and Power Word: Feast: Tempo/buff priest with a lower curve might be more vialble than you think since Voracious Reader is a hell of a card. Combined with Devout Pupil, all the buffs and Flesh Giant, it could see play. Mindrender Illucia fits perfectly in such a deck to take away your opponent's board clear options before a lethal push

-a more face-oriented Weapon/Stealth rogue may also be quite decent, since Secret Passage (easy 5 stars, not 4) is easily one of the most broken cards in HS history, and it also works better with a lower curve

-Instructor Fireheart is an auto-include in any Shaman deck, 5 stars, Blood Herald may have been playable if it could be buffed in your deck as well, only in hand is utter garbage

-Adorable Infestation just does a lot for 1 mana: burst damage, board development, and card generation, definitely better than 2 stars, did you just misread the description? (since you compared it to a hand buff card)

-I suspect Pen Flinger could be sleeper OP in decks with cheap spell generation/draw as a near-infinite 1 mana ping, but not entirely sure on this one

All in all, I got the impression that you have a tendency to sometimes underestimate more aggressive tempo-damage cards and archetypes