Looking great, Kalti!
I've got a quick tip for you on your patch meshes.....
When aligning 2 meshes of similar size, be sure they are the same density. That is, if one is 5x5 (vertices) then make the other 5x as well.
Then, to have a perfectly aligned seam (even after manipulation), select both meshes, hit
V, select the vertex on one mesh, and the vertex on the other that you need to line up, and then
ctrl + K..........Voila! They both now occupy the exact same grid point.......seamless.......
Oh...one more thing...the vertex selected SECOND is the one that will move to the first's position.
Good luck!