Here is a question of opinion (I think):

How should people behave when playing against each other in hotseat?

Especially wrt looking at the other player's screen, resources, etc.
Do you take turns at the monitor?

Do you avoid discussion about strategy?

Turns at the monitor is the way we played it. Leave the room when it's not your turn.

Take a book to read while you wait.

I think, that when you are playing hot seat, it is mostly for fun and you all want to have good time :) and that is what all games should be about - having fun.

Taking turns at monitor kind of sounds like an awkward situation.

I think if you want to play competitively against each other, you should make a LAN party :)

We always did whatever else we were doing (maybe chores), and each player took a short break when their turn came up. Talking about what you were or were not doing was fine, but don't peek at the screen when other player's turns were up.