Still. I don't think it's a good idea to create NIPs with event kinds that replace information in other event kinds. Replacing yourself is fine, replacing the original tags is not (IMO). Even if they come from the same author.

On the other question, the use of a replaceable event destroys the history of changes in labels (relays delete past versions of replaceable events). If we want to use this for serious businesses, it is likely that we will need to keep some historical context for auditing procedures. In that sense, a non-replaceable event structure (like reactions) makes more sense to me. You can save a reaction, you can save the deletion of a reaction, etc. All dates are kept.