I have some ideas. My first idea is making nether quartz useful. Make it the iron of the Nether, and make Venomite the gold of the Nether instead. It means you can craft items with it like crystal sword, crystal bucket, crystal minecart, etc. My second idea is adding a block I call 'Fiery Netherrack' that sets everything near it on fire. Make it the greater diamond of the Nether that you can make armor and tools with. It should look like blood-red Netherrack that is always on fire. My third idea is adding a mob I call 'Hell Demon' or 'Nether Demon'. It should have 10 hearts of health, natural Fire Resistance and a Fiery Netherrack Sword (I came up with the name 'Fiery Sword' but that's up to you, Greenshoes) or a normal Netherrack Sword. It should have bull horns and it should look like a player on fire with a bull's head :P. And my last idea is letting Wither Skeletons spawn rarely in the Nether (they should still spawn normally in Nether Fortresses) and letting them occasionally wielding bows .
Plz notice this and if you can, apply it to the mod, no pressure. And plzzzzzzzzzzzzzzz make this mod compatible with Minecraft 1.7.2