.pull-right is a utility class that’s used in a lot of places, so this would likely have negative impacts! Generally with CSS, if you’re trying to target one element… you want to consider how specific the selector sounds. If it sounds like something generic that could be used elsewhere (like .btn for another example) then it’s probably too broad. Something like .admin-user .pull-right might be specific enough.
Anyway, I’ve submitted a pull request to add some classes to those admin buttons. This should be available in Discourse updates at some point over the next couple of days.
https://github.com/discourse/discourse/pull/16442
Once that’s merged you’ll be able to do any mix of
.btn-user-delete,
.btn-user-merge,
.btn-anonymize,
.btn-impersonate {
display: none;
}