Hi, ErebusMC 
came across your topic, decided to lend a hand.
RTS CAMERA I got quite good with blueprints, will try to make you an RTS camera blueprint - but you might as well just take the RTS example from the marketplace - it’s free - and use it as a base for your project.
MAP GEOMETRY you can use a heightmap to generate terrain, did you know that? You could make one in Photoshop or use a software like WorldMachine. It is going to be a PNG file. Here’s a tutorial I found on Youtube, I’m not the author, but it’s quite helpful.
WATER EFFECTS You could make a material with displacement maps and tesselation, if you choose that method I could just send you my water shader. It’s something like this - though I added translucency and subsurface:
The problem with it is, this kind of water is not interactive - and it does not have foam. It is possible to achieve interactivity with shaders; I’ve seen interactive grass made with them. But I haven’t yet figured out an effective way of doing that.
You could also use the VaOcean plugin:
https://www.youtube.com/watch?v=7REUMOYmVd8
From what the developer says, it’s going to be amazing - with interactive collision, energy based foam and buoyancy. But those features are yet to come.
The third option is to have nVidia’s WaveWorks - there’s a version of Unreal Engine on their GitHub including it, you need to download and compile it - it looks great, but works better on nVidia cards.
