Just to come back to this, It looks like you have your lightmass texture 3 times. Should there not be 1 (maybe 2 if it’s a box) large planes of geometry in UVChannel1? It looks like each on is 18x22 so 396tris. One for top one for bottom. not sure what the third one is for.
For instanced static meshes you would create a blueprint and add instanced static mesh components for each mesh that would be spawned. Then in the construction script set it up to spawn multiple meshes and position them. I thing the twitch stream on level generation from this January covered them I suggest you look at the past broadcasts on that. http://www.twitch.tv/unrealengine/b/607904954