What would you like to have changed or added to Vampirism

This is a somewhat large request, but one that I believe would improve the mod's forest biome in a major way:
Instead of using a custom dirt block, you could use vanilla dirt, and instead replace the grass layer in the biome with Cursed Grass (or something along those lines), which would behave in a similar manner to mycelium and other grass-like blocks, spreading to nearby dirt and dropping dirt when broken.
This would also benefit the spreading mechanic around villages, as the grass around them would be tainted over time and easily cleansed without the need to gather dirt to replace the cursed soil.

Does this make the mod experience more balanced?

Yes, some tedious mechanics would function better and gameplay within the vampire forest would be more on par with the vanilla game.

Can you provide additional resources (etc. textures or models)

No, sorry.