IIRC there is no way to stay neutral because choosing your destiny is mandatory quest in second map of campaign.
I fallowed mainly Tears path for story reasons, so advanced classes abilities didn't have any influence on my choises.
1. Anastasya - Tears - because she is young, naive and undead don't want reveange.
![wink ;)](/forums/images/smilies/wink.gif)
2. Kiril - Tears. I don't know why,maybe because of Xana.
![wink ;)](/forums/images/smilies/wink.gif)
3. Sandor - Tears - I don't like slavers at all, so there was no other choise for me.
4. Irina - Blood - well, after being forced to marriage Gerhart it was logical choise for her.
![wink ;)](/forums/images/smilies/wink.gif)
5. Anton - didn't play him yet but probably Blood path. He seems to me be perfect blood hero - honour and faith above all others and no brain at all.
![:P :P](/forums/images/smilies/p.gif)
To be honest in case of Sandor and Kiril I would prefer to stay Neutral.