The texture missing issue might be the result of missing detail textures. Have you attempted copy over the detail textures from BF2 to BFH (and preserving file paths!) You can find the ground detail textures in the BF2 files here:
Common_client.zip\Terrain\Textures\Detail
There's also the color textures you might need as well:
Common_client.zip\Terrain\Textures\Color
These go to the Common zip archive at the mod's root folder. NOT the one that's in the objects folder!
It also appears BFH has the detail texture folder in the same place BF2 had it. So you won't have to do much fancy work to get it to work.
Also note, your map will likely not be visible in super low graphics mode. You will need to make a "mesh" of the ground terrain with a single texture to it.
That's how Dice did it. Basically instead of using the ground RAW files/detail textures and such for super low mode, they used a optimized mesh. The RAW files are still used as collision of coarse. So your ground mesh for super low mode does not need a collision mesh.