Spot on my friend

Certainly killing all criminals is bad, isn't it? Petty theft shouldn't be punishable by death. There are many times crimes are committed because, just like your Paladin wanting to become a werewolf to prevent evil, one finds themselves in a situation where they feel like the "right" thing to do is to go against the law. Not to mention those wrongly imprisoned due to misunderstandings or a corrupt Jarl or King/Queen.

And how can you be sure all necromancers are evil? It's only a crime in Morrowind. What if necromancers are only practicing on bandits or donated bodies? Necromancy goes on in the College of Winterhold, for instance. Not every necromancer is stealing corpses and kidnapping people for their experiments. Clearing out a necromancer den might be wiping out a whole group of moral scholars that are just trying to find a way to prolong life or understand the process of death.

Becoming a werewolf to hunt the lesser of two evils -vampires- seems a little against the grain to me.

If you are in the service of a Divine, then it just isn't something you would do willingly. An interesting angle, as has been mentioned, is being bitten by one on that you were hunting and how your character comes to grips with this.

But by definition, killing, in and of itself, is an evil act.

For example: Why do Paladins try to take down the Dark Brotherhood? Because they are killers!

So what does a Paladin do, kills the killers for killing people.

You see the flawed logic there?

You say: "if they're not stopped, then what is going to prevent them from committing even more crimes."

I say: They don't need to be killed in order to be stopped.

But then I ask: Why would a Paladin kill a werewolf? Are they killing them just for being werewolves, or is it because that specific werewolf committed a crime??

Being able to transform into a werewolf, regardless of who gave you the gift, doesn't make you any more, or any less, good or evil.
What does, however, is how you use that ability. Do you use it for evil, for good, or for your own basic survival (hunting, self-defense, etc).

Using it to self-righteously slaughter "evil"-doers, to me, comes under the "evil" category.

I have similar problems with the Companions questline, and I have yet to come up with a fitting solution.

For me one important question about this is actually how much control do you really have over the "gift"?

Is the full control the player character has just a gameplay mechanic? Are you constantly struggling to keep the beast in check? Can Hircine force a transformation on you just because he wants to have some fun watching you?

Do people who murder innocents really deserve to live?

But then those would not be the actions of the person behind the fur, so to speak. They would be the actions of Hircine, or the spirit of the wolf.

So then the infected person would be just as much a victim as anyone else. Considering there are cures available, where is the moral justification for killing such a being?

But who's to say they are all innocent? Who's to say that any of them are??

The problem is the contradictory nature of the Paladin: They try to cleanse evil, but they use evil to achieve that goal.

But it's not the Paladin's fault, it's the flaws behind the concepts of what is "good", and what is "evil".

However, if your Paladin character is fine with doing that, then there isn't a problem with them using the abilities of a Werewolf to help further that goal. Because being a werewolf, in-and-of itself, is not evil - the evil comes from the werewolves actions. But, if your Paladin is ok with slaughtering evil-doers, what difference does it make if you do it with a sword, or with a giant wolf paw?? You're still achieving the same goal, either way.

I'm not trying to hate on the Paladin, and I apologise if it seems that way. I'm just pointing out that if you are trying to determine what is acceptable for your Paladin, you have to understand your Paladin's morals, what those morals are based on, and the morals of the actions they already have performed / will perform.

I kind of understood what you were getting at. It's a never ending debate, it can go either way it just depends on how you view things. The thing my paladin does is protect innocents... If that involves committing "evil" acts against bandits or evil necromancers or dragons or vampires or whatever, then so be it. As long as the people are safe. And there lies my answer to my OP, my paladin would most likely, due to wanting to protect the innocent, would become a werewolf, but would pray to the gods every day that he would not be shunned.

I'd argue that the evil comes from accepting gifts with strings attached from daedric princes, which seems out of character for a paladin serving the divines.

But would you be serving the daedric prince Hircine if you did not intentionally become a werewolf?

Find a phone booth to transform and nobody will know it's you!

What are these "strings" you speak of? You practically have full control over your actions as a werewolf. You can transform whenever you want, and you aren't forced to kill anyone. Yet at the same time you gain massive boosts to strength and speed.

The only downside is that the Temples don't like it, but haven't we already learnt to question what society tells us?

Hehe, I travel alone anyway!

Eh, my Idea of Paladin goes far beyond just Killing undead things.

This being, He/she would never kill as their first resolve, but rather try to deal with the situation by any means of not losing more life.

Who would you consider Holier:

Someone who Seeks down a Vampire and kills them in the name of the town he's offended?

Or someone who seeks down a vampire, and offers to help cure him of it, and send him down a road of redemption?

With this in mind, I don't see any good reason why a Paladin would embrace being something that instinctively kills. o.o

Agreed. Shades of grey are much more interesting especially when they introduce themselves to a character of extreme light or dark.

I know when I get infected by a vampire it feels like the end of the world but eventually I learn to deal with it especially if the cure is not readily available.