I totally DON"T need any Vesnali Coins, I buy them cheapest on the spot market after Vesnali is over.

I DO want to give Emma and Esther some bouquets. There doesn't seem to be any game-mechanism for doing this?

if you take a completed bouquet back to the page where you build them, it shows the bouquet and you can click on it. That's the only way to give them a bouquet, but yeah that's just exchanging them. Maybe they don't want free stuff? XD