One of the predictions related to global warming that seems to surprise people is that most of the predicted sea level rise is attributed to the thermal expansion of warmer sea water.
So when we think about major changes in how the ocean absorbs and distributes heat, we’re also thinking about how sea level will change in certain areas vs others. If the ocean starts storing a lot more heat around Cuba than Great Britain, Cuba will experience more sea level rise than Great Britain does.
I don't think that is true. The oceans around Cuba and Great Britain are not separate bodies of water. Volumetric expansion from heating gets flattened out across all connected bodies of water by gravity. You could see differences of geography in how much different lakes expand, though.
I don't know. Consider that a given mass of water would undergo the same gravitational force regardless of whether it is colder/denser/smaller/lower or whether it is hotter/less-dense/larger/higher. Also, as an analogy, consider how much the tidal range [0] varies between areas of the ocean which are absolutely connected as a single body of water. Note particularly the contrast between tides in the Mediterranean and the Atlantic Ocean at large on each side of the Iberian Peninsula, even though they are totally connected through the Straight of Gibraltar.
So when we think about major changes in how the ocean absorbs and distributes heat, we’re also thinking about how sea level will change in certain areas vs others. If the ocean starts storing a lot more heat around Cuba than Great Britain, Cuba will experience more sea level rise than Great Britain does.