Can someone explain Roger’s note (and more generally, why everyone else was writing something on a piece of paper too)? I thought his note was meant to be a quip in that “what the hell did I get myself into” sense, but was that what they all wrote just in case something bad happened to them while they were still on a…

The Pete storyline in this episode reminded me of a line he said back in the first season, something to the effect of "I got this job because you told me that I was good with people, which is funny, because I've never heard that before."

Peggy's shown that she can scheme as well as anybody, but telling on Ken in the hopes that Roger fires him or that Ken is so upset by Roger's reprimands that he quits seems a bit convoluted, even if the endgame would have been for them to move on to a new agency together.

"And did anyone else find Don drawing a noose during the meeting slightly unnerving?"

I don't think Peggy has any motive for telling Roger about Ken's side gig. From what we've seen, Peggy and Ken have a good working relationship and are mutually friendly, whereas Pete still resents Ken's success, although less so than when both of them were still working at Sterling-Cooper.

"I have nothing, Don."