In the long run, the game will benefit if they stay the course with companions. Adding an 8th guaranteed specific card to your hand is good. It emulates concepts that work very well in Hearthstone, Magic's biggest competitor. "Quest" cards and "Hero Powers" in that game are guarantees to your opening, which provide game play with a much needed variance reduction. The difference being that "Hero Powers" are fairly weak, and the deck building constraints on "Quest" cards can be very extreme. Too much variance is bad for gameplay as the game becomes more like Poker than Chess, although some variance is good as it forces players to have to make probabilistic decisions instead of deterministic ones.
Quests eat a card slot from your hand, and hero powers the entire class is based around. They're interesting points of comparison, but they shouldn't be used as proof that companions are within an appropriate power level (or even that the mechanic can be made to fit within an appropriate power level)
I'm listening now, really enjoying this.
I think Scenario 2 (Sequencing Artifacts) I would pretty much immediately go Shops - Vault - Sphere and pass the turn. The Phyrexian Revoker and Strip Mine give good short-term prospects of restricting the opponents' mana, and we can look forward to going off with Mystic Forge in the near future. I don't value the immediate Arcbound Ravager play very highly, given that we are likely to be able to protect Forge and Ravager is just a tiny guy in the short term.
In Scenario 3 (What to Take?) I don't think you've provided enough information to make a correct decision. We need to know what the mana situation is like for the Dredge deck, whether we have a permanent-removing target for Dread Return (such as Ashen Rider), and our Force of Vigor situation. Moreover, I think you are undervaluing Lodestone Golem's 5 attack versus Dredge in this spot. Pitch-heavy dredge lists are generally not winning until Turn 4ish even with dredgers present, and in this scenario you're most likely looking at a couple of turns to find a dredger, maybe an extra turn before you can discard it (1/3 chance), and your legal dredgers now are mostly fairly small, so the possibility that your first dredger doesn't chain into more is a real danger, because even with Bazaar's discard ability you're likely to take some of your draws as draws rather than as dredges. My play would be to take Lodestone Golem and plan to counter Sphere of Resistance or Ensnaring Bridge, depending on whether I immediately draw mana or my opponent graciously runs Bridge into my counter. I'm not afraid of Smokestack at all in this situation (if Smokestack beats me I think anything else also beats me), and I will most likely have a window with multiple kinds of outs to Ensnaring Bridge, such as being able to either Ashen Rider it away or Force of Vigor it, or even simply smack my opponent with 2/2s before they can empty their hand (although then why am I running Unmask?)
In Scenario 4 (Focus on What Matters) my immediate instinct was to hit Hollow One + Leyline and feel like a pretty heavy favorite (my guess: 80%-90%) to win that race. If my opponent Forces I would Force back and we're off to the races, if my opponent doesn't Force I don't think I would go out of my way to keep Force of Will around. You made an interesting case for hitting the two Hollow One, but I think so many of the critical cards in the matchup are non-spells (Bazaar, Strip/Waste, possibly Petrified Field) or spells which don't interact (e.g. your Force of Negation against their Force of Vigor) that your ability to filter your hand is devalued. I think if you hit their two Hollow One you're still a favorite, but it's much more of a 60/40 kind of situation than a simply winning situation. Overall I think the decision is not close.
In Scenario 5 (Speed to Market) I think the "win now" line is likely the best. You have a Force of Will which I think you get to use to push through the win (assuming I've counted out the cards correctly). You are a huge dog to Flusterstorm, but the Demonic Tutor into Duress line leaves you a huge dog whether or not they have Flusterstorm. I would rather take the 60% chance they don't have it than the 10% or whatever whether or not they have it. If you only have 1 Force of Will as disruption and they build in 1 piece of counter-disruption you're either dead or needing to topdeck extremely well. The Necropotence line seems like a worse version of the "win now" line, given that you need just as much disruption superiority but then you're not winning for sure at the end.
Is Thoughtcast with multiple creature type requirements that good? Feels like a Ux Fish kind of card, seems unlikely that it should be strong enough to get restricted
The current restricted list has a number of Xerox-ey cards, but I don't think we've ever had a restriction that really hit Fish-type decks more than other archetypes.
Fishlike decks tend to be pretty reactive and metagamey, which makes it hard for them to become really dominant