Hi WWtrain.
I looked over your plan and thought I’d offer a few suggestions.
One of the main areas I think you’ll have problems with is the yard (I’m assuming that is the cluster of tracks in the upper left hand corner of your plan). Since that part is against the wall I’m sure you’ll have trouble reaching the tracks and cars during switching. In the plan below I made the yard stub ended and moved it to the front of the layout for easier reach. You can now add a turntable if you like (though it will make the area look a bit crowded, but that’s your choice).
Another problem I see is having the line to the mine cross over other tracks. By moving the line to the outside you can have a gentler grade without having to worry about clearances. Also, just for convenience I added a runaround for switching the mine.
In the plan below I kept the industry spurs as close to the left side as possible for easy reach. I also made the plan a dual mainline for more interesting operation. If you’d like, the two mainline tracks on the right can be moved closer to the mine and still be in a tunnel without the mine directly overhead.
Finally, I included an interchange track on the bottom right. This can easily disappear in a tunnel to represent a connection “beyond the layout”. This frees up space in front of the dresser (if you prefer, you can still use the turnout to connect with the extension you drew).
These are just a few suggestions I thought you might like to look over.
I almost forgot to mention: the minimum radius is 13" which is considered conventional for N scale.
Vic