Re: If ESA was smart
Superheavy boosters will not splash down - they will return to the launch site and land again for re-use. Apart from that, I agree that French Guiana is an excellent launch site.
Long term plans for Starship includes becoming a competitor to long-haul air travel. The noise level would restrict landing to ~20km away from the coast. Not sure if French Guiana is a popular enough tourist destination to get one of the early landing sites but coastal European cities are like a fairly high priority.