@FediTips
Great, thanks for explanation.
Didn't know author of the post wouldn't be notified, if I don't mention them. Assumed it would be automatic.

Whole interface for posting/replying still confuses me. I guess it's more or less copied from twitter, but I never used it, so ui looks a bit alien to me

And part about "reply in thread" - when I hover over reply button it sometimes shows a hint with those words. Now I noticed that it actually only showed for replies to replies.

@FediTips
Hi FediTips, I have a question, can you help?

When commenting (is it called "replying to thread" here?), @ handles for everybody in thread are automatically added to post (at least in the web version).
Is it safe to remove some of them?
And do I need any of them, if I only want the author of the specifically message I'm replying to being notified?

@FediTips

I would like to say thank you for your work!

I was wondering what is the PixelFed, I've seen mentioned around a couple of times. And then I've seen somebody boosting this post, found your site.
And there - all the answers to exactly the questions I had!
This is immensely helpful to people just arriving here and dealing with the complex new world of Fediverse.