newcomers | Couple questions about tagging etiquette

EDIT: Thank you all for the guidance! I think I've got a pretty good understanding now.

Hello all!

I'm very new to Dreamwidth (showed up with the latest wave of Tumblr ex-pats) but thinking about using it to post some of my media-criticism thoughts that I've been collecting in a private journal for the last year or so.

However, I want to make sure I can tag these appropriately, so I have some questions.

1. What's the etiquette for posting tagging discussion of a piece of media that paints it in a negative light?

On Tumblr, it's often considered rude to bash something in its main tag, so if I wanted to make a post criticizing the Marvel Cinematic Universe, I'd tag it something like #mcu hate so that it doesn't show up in the main #mcu tag where people are trying to enjoy their thing.

(I'm primarily asking because I have some quite critical pieces about Harry Potter.)

2. Does Dreamwidth allow users to block tags? Is this something I should anticipate when tagging entries?

On Tumblr I'd tag something like #eating disorder / to hide it from people who are avoiding that topic, including the slash so that the tag isn't searchable (on my own blog or in general). Is that a thing here?

I think that's all I've got for now, but I'll probably think of more later.