I’ve got my defaults set to “all” and “active”. It’s my understanding that “all” shows instances we’re federated with, whereas “local” will show only Hexbear posts. I am seeing some non-hexbear posts on “all”, but it’s mostly Hexbear. Are we simply the most powerful posters and therefore take up the front page or is it weighted behind the scenes to still favor local?
No complaints, I’m enjoying federation so far. Mostly because I’m only seeing posts from other instances talking about how cool we are 
Yes, subscribed will show you all of the communities you have joined (or subscribed to), regardless of which instance the community is on.
So yeah, imo, curating your own list of comms that you’re subscribed to is the best way to use Lemmy.