Force of Rage is unplayable trash fyi. It exiles at the beginning of your upkeep, not end step like you'd want it to, so it's mostly just Ball-Lightning, which hasn't been good enough in 20 years.
I realize it was upkeep, but being RR1 instead of RRR ,and two creatures instead of one, can all generally be considered upsides. Plus, the fringe cases of using it as surprise blockers/removal on opponents turn.
Don't get me wrong, I doubt it's shaking up modern, but I wouldn't be surprised to see a couple copies make it into some tier 2 decks.
I do agree they missed the mark slightly on the marketing. They made it sound like they'd be drastically changing modern, but I doubt that was ever their intent. I think there are more playable cards then you are suggesting, but mostly for all the tier 2/3 decks. I know a local guy who has been playing a slivers deck for years, has won qualifier tournaments with it even, who is gonna love this set. I believe WOTC's intent was to try and give more toys to all the lower tier decks, not to add anything significant to the tier1 decks, and hopefully spawn some new ones in the process.
As for the cards, I think there is quite a number of cards that look fine. Archmage's charm, Plague engineer, Ranger-Captain of Eos, Force of Despair, Cabal Therapist, Flusterstorm, Force of Negation, Sling-Gang Lieutenant, FoF, Regrowth, Prohibit, Nimble Mongoose, Wrenn and Six, Ice-Fang Coatl, Lightning Skelemental, the horizon canopy lands and Prismatic Vista.. all seem to range from clearly playable to 'potential sideboard tech'. Considering how big the card pool is for modern, that's a decent ratio of playable cards for one set. Some of those look like they'll be good in legacy, even. I don't see any that scream 'broken' and will spawn a completely new deck, though, which is what I think people were expecting.