Setting water higher or to max would probably actually be more difficult than setting it only to starting area. Unless you have the misfortune of only having a single tiny puddle that cannot even support your oil industry, it's not going to run out, it's an infinite resource! It won't even slow down to a trickle like oil (Though maybe in future updates we will have to consider the water drying up if we go through too much too quick.)
If there's water everywhere though, that means less room for resources. It will be harder to plop down your factory and solar farms, and all the water in the world isn't going to make steam without fuel which will be less abundant as you can only find fuel on land. The only problem with this is though that I believe setting water higher increases the likelyhood of being on an island. You don't want that, you want a world that is actually infinite so that you actually can get the resources if only you spread your fingers far enough to reach.
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On my most recent playthrough I have set most of the resources to the very low settings, with exceptions as I didn't want some brutal hard mode, I just want to have to go further and have more room to do things. I'm just getting to the point of setting up roboports (and planning for train stations) so I can say a few things about the early game.
I set oil size up one notch and frequency to minimum because I don't like having tiny oil operations spread all over the place. And I set iron size (or frequency, one of the two) to small as I find copper to be more plentiful on equal settings and I thought it would be interesting to not have iron be the constant bottleneck for everything. I set starting area to big or very big, biter size small, frequency high, 'richness' very poor (Does that make them evolve slower? It's hard to tell if it does anything), and it has been a pretty good balance of difficulty so far. It's pretty hard to have the resources to expand your operations, tech up but also defend at the beginning, and I won't lie I've reloaded my save quite a few times so I can respond to attacks at undefended places and not have my storage chests be destroyed. I'm sure at a certain point I will have the strength of will to do a No Save Scumming runthrough, but today is not the day.
Overall I've quite liked the experience, though I've crashed into one too many poles with my car. It hasn't been too frustrating but I'm sure it would have been a much bumpier start if I wasn't so generous on the biter settings.