Why does it seem like green has become extremely power crept in the last few years and can do almost anything except "destroy target creature" (and that is debatable with stuff like the etb fighting hydra recently printed), but white and red are vehemently not allowed to come close to the sheer magnitude of things green can do? For example, green gets rewarded for doing green things, but white can't be rewarded nearly as much for doing what white likes to do?

White can be rewarded for doing white things. The reward though have to be white rewards.

What strategies, if any, does Wizards take to avoid power creep? Or at least, make an attempt to curb it?

I did a whole podcast on it. We call it the Escher Stairwell where we lower one aspect while raising others, so it appears like it keeps going up while actually staying steady.

Is power creep reversible?

Only in formats where things rotate out.

Is there a static target power-level for standard sets? If so why have one power-level as opposed to having it vary, since anything undesireable will cycle out later?

We keep the overall power level of Standard somewhat consistent to avoid power creep issues, but we do ebb and flow the power level of different effects.
In Standard A, for instance, direct damage might be at the top of what’s allowed while land fetching might be weak while in Standard B, direct damage could be middle of the road while land fetching excels.

Why not just make standard stronger so we can actually get impactful reprints of modern cards? You say "the power level of standard is supposed to fluctuate, with some sets being stronger than others", but the fact that standard hasnt been strong enough to support modern reprints since somewhere around m11 or m12, that doesn't seem to be the case. If anything were further away from a lightning bolts and Giants standard than ever, and that's a real waste.

In order to make a format with two years of cards powerful enough that it can easily include numerous cards that stand out in a format with fifteen years of cards, you’d have to make it insanely powerful and cause major power creep, neither of which would be good for the long term health of the game.

Can you explain power creep?

It’s constantly increasing the power level of a game to make the new things more exciting.

" Are you taking suggestions for future point/counterpoint articles? If so, may I recommend power creep?That requires someone advocating power creep which neither Sam nor I want to do." How about making beneficial abilities 'may' abilities or not?

That one has potential. I think Sam and I might actually be on opposite sides.

Hey Mark, over the last 5-8 years we've seen a serious power creep in relation to creatures, is there any plan to reel that back a bit for those of us who love to cast everything else?

Go back and look at the best creatures 5-8 years ago. If you compare them to the best creatures now, they aren’t more powerful. I would argue they’re a little weaker.

As an avid listener to your podcast and a long time magic player, I love the credo "restriction breeds creativity", as well as much of your design philosophy. If restrictions lead to creativity, why does R&D always create "pushed" cards in each set? They seem to be saying; "Hey, do what you want, be creative, but also you must play with these 8-16 cards of you will just lose."

We want each set to be relevant to Standard, but if every card was potentially tournament viable, we’d create massive power creep. So, we choose a group of cards (far more than 16) that have potential for tournament play and let the players steer the meta game.

So is red getting 2/2s for 1R with no downside okay now?

Apparently.