Great job, good advice. I think Mercury usually carries around 1800-2000 pax, not 2500. Its funny to hear her described as a mid-sized ship. A few years ago she was a "megaship" and the Horizon/Zenith were known as "mid-sized" ships.
I with you about the cabin choice not being a big deal, but some people have come to love their veranda cabins and those in suites get perks.