Regarding point 1:

Makes you wonder why some (too many, really) companies are putting SE managers through the same coding interviews that they do with junior engineers.

As it turns out, when you've been a manager for years and years, coding hasn't been part of your daily work for about just as long. And when you decide to join another company, to continue to work in a managerial position, there's gonna be just as little coding there.

But still they insist you to do the same cookie-cutter DS and Algo questions.

(Note: this obviously doesn't apply for every company - but there seems to be a lot of cargo-culting going on, and trying to generalize the interview process for everyone in the industry)