Does an oracle with the vampirism oracle curse actually need to drink blood, have fangs or have any problem with sunlight, garlic or other such things?
The vampirism curse only comes with the mechanical effects described. Your Oracle is free to role play those other traits (maybe they get sunburnt easily, or find garlic unpleasant), but they aren't actual mechanical weaknesses.
Per RAW, no. The only mechanical impact is that Channel Energy affects you like it would Undead.
Personally, if they made you an actual vampire, you'd be pretty powerful compared to the rest of the party that isn't a vampire. You'd also have the Undead type, and a bunch of other rules to follow.
A better way to look at it is that you're more like a Dhampir, whose "bloodcraving" is technically optional.
Ah good, I thought as much, but didn't want to assume. Thank you.