1) Huh?
2) First you need to select the sectors, either>
a. Hold down AltGr and drag the mouse cursor to select the sectors (they will be hilighted yellow)
b. Hold down RCTRL, aim at the sector(s) you want to select, hold down ' and tap AltGr to select it. You can select multiple sectors this way by not letting go of RCTRL. ; to deselect.
Press Insert to duplicate, or while having the sectors selected (hilighted yellow), load another map and the sectors will be loaded into the map.
3) Two ways
a. Select the sectors with the method above, then you can press X or Y to mirror the sector in either direction.
b. For proper rotation, select the sectors (or sprite stacks) by just left clicking the mouse and dragging over the selection you want to rotate (you can also hold down RSHIFT to do this). Then just aim at one of the vertices or sprites, hold down LEFT SHIFT and drag with the Right Mouse button held down.
You could also use the mapping questions thread:
https://forums.duke4...post__p__243730