@Harold: This is KaM Editor topic. Sorry, I must have overlooked your TKE topic here in this forum, where is it? I'd really like to contribute to it

I agree. There should be a TKE thread on this forum.
Copy/Paste is technicaly done, now I work on making it handy and user friendly

Concept so far:
1. click "Copy" in menu
2. left click sets left corner of copy area
3. right click sets right corner of copy area
4. open new map
5. click "Paste" in menu
6. left click pastes copied area starting from upper left corner
or right click pastes copied area starting from lower right corner
7. use Undo if something didn't fit
I have a better idea:
1. Click Copy in menu.
2. Left click the top left corner and drag to the bottom right corner. (an outline displays what you are selecting) When your cursor reaches near the edge of the editor it auto scrolls across.
3. Open a new map (unless your pasting into the same one)
4. Click Paste. The section you copied is now displayed under you cursor, just like a really large tile. Click to paste it.
You would need to be zoomed out a long way for copying/pasting large sections.
This would be more controlled, plus more user friendly. (although it would be more work to program, so do it how you want to. The way you suggested would still work ok)
Another suggestion: A "Lock Tile" tool. You can lock and unlock tiles. Locked tiles will not be changed by the smart tiling/random tiling. This would make walls/bridges easier, as you could lock them and then place the water under the bridge, or the ground next to the wall, without the auto tiling destroying your work. Just pretend the lock tiles are the same type as the tile you are placing, then you could do the ground next to a wall. Not a very important feature though, some of the other suggested are better.
Lewin.