H-Mode7

[JayRay]

Unfortunately, from what I've seen, I can help with only a little bit of this.
1. Ah the infamous tiles. underneath things.... again, this can be canceled with a basic ground layer
2. Check your Hmap, you might see that there is a line of white in your map
3. The bordering problem of textures at the edge of a map is sadly not currently changeable. however, I have seen where by loosing a layer, and creating a ground TILE for everything, the texture sometimes stick, much like a cross section. But this would drop your total n-layers from 8 to 7
4. From what I understand, Flat eventing is not possible in the current H-Mode 7 manifestation. I would love this to be the case myself, for bridges and whatnot, but sadly it doesn't seem to work like that.
5. No way to change the texture to 64 by default, but you CAN use player zooms to make your characters appear smaller in combination with the tiles.