Whether or not this is better than Swan Song is entirely dependent on the deck youre playing against thisll completely whiff versus that Melek, Izzet Paragon entirely-spells deck, just like Swan Song whiffs versus aggro decks
No, you cant copy emblems
This might be relegated to a sideboard card for the decks that need it, but itll absolutely perform that function incredibly
Some might argue that you can cut down your Swords to Plowshares to three copies due to the added possibility of dealing with Delver of Secrets via Red Elemental Blast, but I wouldnt advise doing so because there are still too many creatures outside of blue that deserve our attention
The Thopters created by Breya, Etherium Shaper or Sai, Master Thopterist can chip away at your opponents' life totals and be sacrificed after combat
You can play peacemaker at the table, keeping heat off yourself, while quietly positioning for your own win