Welcome, let's get right into this.
First thing, the file is not clean, learn about cleaning here:
https://www.tamriel-rebuilt.org/content ... e-tutorial many items are dirtied:
and cells without landscape data can be cleaned out in files like this or exterior claims,
You should also clean out the islands that aren't for review.
I noticed that you are using a LOT of different regional rocks, rocks only get mixed like this in region transitions, and even then its 2 or 3 regions at most.
Next issue I noticed is how the ice chunks are all evenly spread and uniform in a lot of places,
but you had the right idea keeping them closer together and not going as far out into the ocean here:
Your island has default land texture showing, this shouldn't be seen so close to completed areas.
Very steep terrain should be covered with large rocks to cover stretched terrain textures.
I can't see very much vertex shading on the island, you need to have a dark shading under statics and a lighter shading between landscape textures and between ground and water.
The terrain on the whole island is rough and jagged, smooth it with this:
There are a LOT of landscape texture seams:
Seams happen when more than 2 textures are touching, cover them with statics.
This looks weird
The rocks underwater are very evenly spaced, and very repetitive, you also don't need this many rocks underwater, when you decide on a single region rock type to use, make sure too many of the same number aren't too close together.
We need some more buildings and walls in this fort to show you can work with grid/angle snap
The roads and hills should be less straight and square to be more interesting
Roads need to be sunk into the ground to look traveled on, as seen here
https://www.tamriel-rebuilt.org/content ... ding-guide
Ice sheets like this are meant to be tiled with gridsnap with other, similar pieces
You have statics hidden under terrain:
A lot of work still needs to be done, but I can tell you made a good effort.