What exactly do you mean with that?
Yes, this mod messes with the night vision potion, but it should still work even if you are not a vampire.
If it causes problems for you, please report the your Minecraft and Vampirism version as well as a more detailed description.
There actually is a feature to adjust the eyes/teeths. Use the "/vamprism eye <number>" (or fang) to try different eye types.
The settings you suggested would probably provide a better way to configure it, but it would be quite time consuming to implement properly and I don't think it is worth it.
Regarding skins. Yes, some could use a redesign, however, the use of HD textures in a mod is rather bad practice. If your friend would like to create 64x32 skins, he can submit some if he likes.
If you are looking for higher quality textures, you can always use a texture pack, e.g. this BDCraft addon by Gedankenspiel http://gedankenspiel.me/vampirism/
so basically allowing human players to use vampire abilities? That would kinda defeat some of the basic concepts of this mod?
But a "lite" version might be an interesting idea for servers/modpacks , where not everyone wants to get deep into Vampirism, but might be interested in some of the features.
Or did I misunderstand you?
i mean, this type of vampirism is special. you don't just need the stone to get this type of vampirism, but also a soul of a REALLY powerful vampire lord.
and this isn't the normal run-of-the-mill vampire, either.
this vampire is meant to be something out of castlevania.
ie. flame attacks, summoning bats as a projectile weapon, using souls as well as blood to heal, transform into mist or a wolf, and a giant demon form.
this is what i call "the dark lord". one where the very air around one perpetuates a dark atmosphere (as in, the immediate area around a dark lord would always be nighttime, unless canceled out by an equal power). one that can summon a giant castle (as in, a pocket dimension which houses your giant castle.), and command an army of undead (able to summon x amount of zombies and skeletons.)and who knows what else. one that only an equally powerful vampire hunter (yes, i do propose an opposite power to a dark lord for balance) can slay.
if you have ever played lament of innocence, this is how dracula became, well. dracula. by sealing the soul of another vampire lord inside of the crimson stone.
this can't be any vampire. it HAS to be an especially powerful one or else the stone will reject it. and you'd have to first FIND the crimson stone too. and dropping or throwing away the stone would cure the vampirism. but, if another person were to obtain the stone dropped, they would have to kill another powerful vampire.
in a sense, this is a different type of vampirism, one that requires gaining dominance over another vampires soul, and with it, dark and terrible power.