Is an Ooze or something with Ooze traits a living creature for the purposes of things like
If we look at the entry in the SRD we see:
So it is, unequivocally, a creature.
As for living, the entry doesn't say that they aren't, unlike construct:
And an Ooze does fulfill the major requirements of most definitions of life:
(I'll assume they reproduce, it just doesn't often come up in game except for the varieties that split when you deal them enough damage)
Check the creature's Type in the glossary of the Monster Manual. Undead and constructs share the following trait:
If the creature's type does not have this trait, then the creature can be affected. The MM glossary entry for the Ooze type (p. 312-313) shows that they do not have this trait. They are, however, immune to certain other affects: poison, sleep, paralysis, polymorph, stunning, and mind-affecting effects (and blinding, since they have blindsight).
I would classify Vampiric Touch as an energy drain, for this purpose, though the spell description isn't that specific.
If we look up the Ooze ( http://www.d20srd.org/srd/monsters/ooze.htm ) itself, we find that: "Oozes are amorphous creatures that live only to eat." So the answer, if we take even description as word for word canon, is most likely "yes". :)