I'm pretty sure both are correct at Union St and 5th Ave. The Manhattan Savings Bank building (left edge in both photos) is still there, and fairly distinct.
Classic MacOS did, but it's definitely not something needed for multitasking without an MMU. For instance AmigaOS didn't do this, but instead effectively had a single shared heap.
Yes. The Amiga text terminal allowed you to shift the top and left margin by single pixels using escape codes. After shifting, writing new text would not overwrite pixels outside the character cell, so by writing a line of text, and then shifting the margin down one pixel, writing another line of text, etc. you could get a complete bitmap image displayed.
There is a lot of unnecessary information in your hypothetical message. What, beyond "[name] plans to rendezvous with [family member's name] at [rendezvous point] (about [time])" needs to be conveyed? Suddenly it's a very different message.