I can answer the A.
To get textures from Bedroom or any other map, just type its path while assigning textures. For example, if you want to have the roof texture from Bedroom in your map, either:
1.If you are using Mission Editor, just browse wanted texture and add.
2.Doing it from .mis file: Find the texture section, type path: (this part varies)/Add-Ons/Map_Bedroom/TT_asphalt01.png ,with the asphalt texture replaced with any texture from other map.