Given how strong answers and threats are in Standard is Counterspell / Mana Leak still considered too strong? Or is it just negative connotations from sins of the past?

Power level is not my forte.

Is there much design space in white having counter spells that counter unless the opponent pays a cost (like mana leak and quench) to fit in with a taxing theme while letting blue have hard counters/counters with benefits?

It’s not a design space issue. It’s how much white counterspelling do we want.

Ward is, IMO, a Hexproof that works better because it gives opponent the choice to circumvent it for a price. I have always thought that Counterspells, especially in matches where sideboarding isn't a thing, are too hard to play against. How do you feel about making Counterspell be like Ward by default and allow the counterspelled player to cancel the counterspell for a price (i.e. a little like Mana Leak)?

Counterspells have to be costed correctly, but do come with a real cost for the caster. You have to not do things to leave the mana open. I think having some conditional counterspells is good, but I also think the counterspell player should be able to depend on some of them. I think a mix is what creates the best overall gameplay.

By taxing counterspells, do you mean something like Mana Leak?

Yes.

Hi Mark! Curious about the space for a white counterspell... Could white get an unconditional counter effect if the set up was very difficult? Like if it could only be cast during combat and/or required you to have a creature?

No. It can delay (Memory Lapse) or tax (Mana Leak), and at a lower power than blue. That’s it.

What's the difference between Mana Leak-style counterspells and the Rhystic mechanic?

Mana Leak my opponent has to have it in their hand. Rhystic spells basically gives my opponent a Mana Leak every time I cast a spell with it. It’s the difference between your opponent doing something to you and you doing it to yourself.

How firmly is taxing in blue? I see a lot of blue effects that make spells cost more when they target blue's creatures, but otherwise taxing seems pretty sparse in the color. In the WAR DTW, you said Dovin's static ability was a bend in blue that was at least partially allowed because he's a hybrid card.

Blue is secondary to white. Blue also taxes quite often on counterspells with things like Mana Leak. White does it more, but blue has access to it.

Since white can do taxing counterspells, could we ever see a white mana leak?

In theory.

Having exactly one powerful counterspell in standard (e.g. mana leak, remand) would not allow a "draw-go" deck to exist (using your definition of "draw-go"). The deck wouldn't have the tools to counter most things its opponent does, just a few things. In light of this fact, why has it been years since we saw a powerful counterspell in standard?

One of the problems with having a game with fluctuation of power level, and being over twenty years old, is that players define “powerful” as the historic peak of an effect (rather than use the term to mean impactful in the environment it’s played in).Current Magic has done a lot of rebalancing of effects to create a more level playing field. Historical “powerful” cards are often hard to bring back, because they majorly warp the environment.That’s not to say we can never do it but it comes at a very high cost and thus isn’t something we can do very often.

Spiritkhan is asking what you think standard/limited etc would be like if you hadn't dropped the power level of instants and sorceries (eg: no one cmc kill spells like Bolt or Path, scarce numbers of two cmc counterspells like Mana Leak or Deprive, and even fewer 2 cmc kill spells like Doom Blade etc etc etc)

I think it would be worse, which is why we did it.