hi im fairly new to scmdraft 2 and im learning how to make extended terrain. i was a bit dissapointed to find there are no tutorials on terraining. it would be cool if someone could do that. more to the point, im trying to flip/mirror/invert some terrain horizontaly. is there any way to do this without recreating the tiles 1 by 1?

With Isometrical terrain you can use SCM Draft to mirror it, however, with extended terain(ie, blocks) you cannot.

Not possible at all.

There are however, pre mirrored tiles created by Blizzard (doodads with multiple faces often have near mirrored terrain as their counterparts.