Yes, when SEC asks for something it's considered governmental intervention even though they technically don't force it.

Probably not any, but my understanding is that the answer to that is mostly yes because much of the incentive for these entities to self-regulate comes from the threat of worse-for-them regulations from SEC if they fail to do so in a way that SEC feels good about, and they spend a fair bit of energy communicating back and forth what those ways are, even if it's not made explicit on paper.

Look at the language of SEC (and other regulators outside of technical fields like pharma).

There are very occasional "landmark" regulations, often legislated, that are explicit. EG Sarbanes-Oxley.

Day-2-day, the SEC works mostly by signalling. They might make a policy declaration, or send letters to CEOs. They'll note things in periodic firm reviews. Publicly raise an eyebrow. Take action against or investigate one firm and publish findings. Rarely are specifically worded edicts issued.

Regulating bodies are designed to work largely through pressure instead of (ironically) through regulations. This is by design. Regulators are usually created in response to firms having won the loophole cat and mouse games, and the prohibitive complexity of actual regulations. If government wanted rules, they can just legislate directly instead of delegating to a regulator.

"Compliance" is often about staying away from trouble by playing a sort of guessing game. It doesn't mean that it's "hands off."