1. Agree with previous Posters, River/Floodplain Floods (and Volcanoes) have been much more persistent Disasters in my games so far. On the other hand, having to 'park' a Builder in a city to almost constantly repair damage is annoying, but certainly not Game Breaking.
2. Even more agree, Civ VI seriously underestimates and under-represents the advantages of coastal positions and especially sea/river Trade Routes.
The major separate advantage of the coast is Food. We've depleted fisheries so much in the last two centuries that we've forgotten just how much quality protein came out of the coastal waters - and fishing a rich set of waters like the North Sea, Baltic Sea, Sea of Japan or Chesapeake Bay, or the Grand Banks off the northeastern American coast was far more reliable than hunting - or even farming, which could be devastated by drought or general bad weather.
And they still have a long way to go to represent the importance of maritime trade. For one thing, as mentioned previously, maritime trade extended far inland over major rivers, but for the second, there was a lot of trade that was Impossible except by water: no overland trade route before railroads could carry enough food to be significant, for instance. If you are trading any industrial (Strategic) goods: Iron, Coal, Niter, you are trading in tons of the stuff, and a pack train simply won't carry enough of it.
At a minimum, not only should Sea Trade Routes be at least 2x the length of land routes, there should be no Food from land trade routes, only small amounts of Production, Science if the origin city has major Science 'production' to trade, and Amenities. You want to move Food or Raw Strategic Materials, you will have to go by Sea until railroads and later mechanized land transport.
3. Hurricanes are devastating, but they should be very limited geographically. You don't get hurricanes hitting Seattle, for instance. You don't see a lot of hurricane activity affecting Glasgow, Lisbon or Vladivostok. The game should be much more 'selective' in Hurricane spawning and movement, so that, like floods and volcanoes, you have a pretty good idea where to expect them. I had a hurricane swirl in to a city on the coast on the edge of Tundra tiles, which is a little like having a hurricane hit Oslo or Anchorage!