Just one thing.
Add http to that. Pokecommunity doesn't allow me to post links.
Ok let's start with the flames in the background.
What you have forgotten to do is set a transparent colour, or to be more accurate a helpful transparent colour. You need to change the first pixel on the image (the top left hand corner) to a colour you won't use on your background. (So for example for you you could use a pink/red). You would probably need to do this before indexing the image. Make sure you make a tile that can replace the transparent colour pixel bit when you put it on NTME. And on NTME just don't use that block. To check which colour is your transparent one, go on IrfanView and go on Image>palette>edit Pallette and the first colour there will become the transparent one.
To remove the *shudder* glitchy tiles, I can only assume your background is not fulfilling the three sacred rules.
Let me know what happens and I'll see if I can help more :)