Question

I am double checking, really, as I think the answer is no: Can I hide bodies of water which aren’t seas/oceans, i.e. lakes. A client is commenting that these smaller bodies of water make the maps look “complicated”.

Here’s my styling rules:

fsdStyles = [
        {
            featureType: 'all',
            stylers: [
                {visibility: 'off'},
                {hue: '#00162b'}
            ]
        },
        {
            featureType: 'administrative.country',
            stylers: [
                { visibility: 'on' }
            ]
        },
        {
            featureType: 'water',
            stylers: [
                { hue: '#002f56' },
                { saturation: 85 },
                { lightness: -84 },
                { visibility: 'simplified' }
            ]
        }
];

Answer 1

No, you cannot turn the features you describe off. And there is only the single feature type: water, there are no sub-types, so there is no real way to style lakes in one way and oceans in another.