Knights of Tezoth

How much must one abandon dignity and conscience in the service of Carneia?

In terms of conscience, you need to be ready to carry out the most cruel orders. In terms of dignity, it depends more on luck and caution — if you're lucky enough not to trigger her, you can go through your entire "career" without incidents. 

Does the ritual of being knighted involve kissing a boot or some similarly humiliating ceremony?

With her, chaos and randomness prevail over customs — it could be a boot, some kind of foolishness, or some kind of cruelty. In principle, you can describe in your quest how it went yourself, but it's better to check with me first.

How bold can you be with her without consequences?

Depends on her mood 😓 But you must always know your place.

Like, could she order you to give your wife to other knights for "entertainment"?

She could do that if there's a reason (you fail a quest, for example), provided she considers your romantic relationship with her to be very good. If it's just a static spouse, she wouldn't even think of it. She likes to strike where it hurts, in general. 

Or order you to torture servants for not pouring 2 grams of wine into a glass?

If she broke a nail that day, maybe. And not 2, of course, but something a bit more noticeable.