No worries, I’m sure Norton Utilities will fix it.

Apps like Signal and iMessage allow any emoji. I don’t have a strong opinion about a limited set vs any defined in Unicode.

I’m not sure this is possible since reactions tend to be in the context of the comment. For example, if a comment is expressing anger at an injustice, an angry emoji would probably be interpreted as “I am also angry” at the injustice and not disagreement or anger about the comment. If someone is expressing a personal loss, a sad emoji would me likely mean sympathy.

One of the best pieces of advice I have ever gotten was to build diagnostics first. The time it takes to do will pay for itself 100X over the course of development.