This is great.

Thanks!

I've not created a magazine but I've been curious about how Mods associate microblog posts with the magazine. I'm assuming that's through the "Tags" tab you describe on the moderation page.

Yep. Any tags associated with a Magazine will pull in those posts that include those tags.

one is the distinction between upvote/boost

Upvotes (Favorites) are like reddit upvotes and boosts are like Twitter's retweets. So when you favorite something, you are saying, "Hey, Fellow Subscribers, this is interesting." When you boost something, it is like saying, "Hey Fediverse, check this out!"

how to subscribe to an entire instance

To subscribe to an instance:

1. On the channel, click the instance name. (For threads, it is next to the title.) Alternatively, If you know the instance name, you can enter the url https://kbin.social/d/<>. For example, https://kbin.social/d/lemmy.world. Either of this methods will land you on the instance's domain page.
2. On the domain page, click subscribe located in the side panel.

Thanks for these questions! I will add them to the Guide.