You can change the texture and mipmap size if you want, but the default is usually alright. It depends on how powerful your PC is, if it's very good you could probably handle somewhat higher settings. When you get to the distant statics part of the generation process, try setting the statics size to 150. This is the minimum size statics have to be before being rendered by MGE. So the smaller number you pick, the more small objects you'll see. 150 is fine if you want MGE to render most buildings and large rocks.
It's only after all this that you decide how many cells you want MGE to render, on the distant land tab. A draw distance of 5 cells allows you to see a lot more, but not the point where you can see the whole island.