Looking good. You will want to take a close look at this article on
dimensions and make sure you are paying very close attention to how your map will line up on the grid.
All unit starting positions need to sit squarely within the 32x32 grid. Any brushes that extend more than 4 units into a 32x32 grid will make that grid tile un-walkable in-game.
The easiest way to catch problems is to compile and load the map in-game often. This is easier while your map is very small, since the compilation will go quickly.
A couple tips that might help you:
1. There is a useful "fit texture" button. Select the face of the asian artwork in your house and then go to the Surfaces tab. Click the "Fit Texture" button and the texture will automatically be rescaled to fit the brush face.
2. When you go to raise your map up 64 units so that the level 2 starts at 64 units high, you'll want to use the Lock Texture button. It's the bottom button on the left panel and it will prevent textures from moving around when you move the brushes.
3. A lot of your textures are scaled at 0.5. For some reason this is the default setting for UFORadint. But usually you will want textures scaled at 0.25 to 0.125 to not look too pixelated in game.