[naked_lego]

Since these are fantasy questions I'm going to treat all of them like I was a fantasy character. Where it seems the normal laws of the universe don't apply (i.e. taking more punishment then a normal person could stand and still be able to get up again.)

1. After getting caught trespassing in her castle, you've been captured, thrown into a dungeon and chained up by a beautiful witch (think Bayonetta, for example). She offers to forgive and release you, but only after doing a favor for her. You can either have her cast a spell to temporarily shrink you while she uses you as a dildo, or you can have sex with her dragon, who is the opposite sex as you but whose sexual fluids are painfully spicy.
This would be more of a decision if the dragon didn't have painfully spicy fluids. I can't really handle pain for spiciness so I pick being shrunk.

2. You've been abducted by a group of centaur-like aliens who reproduce in a very different manner than Earth creatures and are studying our form of sex and reproduction. They want to know about the limits of what human genitalia can withstand. They give you the choice of having your urethra tightly sealed shut (if you're male) or your vagina densely filled with sand and sealed shut (if you're female) and then being masturbated by them until you've cum three times; or being forced to be stimulated with a machine that fucks you with a realistic fleshlight or dildo for 24 hours straight.
I think I'd choose the machine for 24 hours. Althought 24 hours is a long time and I'm sure I would be sore beyond belief. I don't think I would want any part of my sealed shut.

3. After being allowed to recover from the previous punishment, the aliens reveal that they have shapeshifting powers that allow them to turn into any animal they've seen and have the power to grant you such powers as well. However, if you accept the power, you will have to have sex with the aliens ten times as ten different animals, including birds, reptiles, mammals, and insects. The other aliens will always shapeshift to match the type of animal you choose (if you temporarily made yourself a dog the alien would temporarily make themself a dog of the opposite sex, for example). Do you take the shapeshifting power or not?
Yes, I would take the powers!

4. You're walking through an enchanted forest naked when you accidentally bump into a nest of magical Miracle Wasps, damaging it. Immediately the entire hive swarms out and prepares to attack. You try to run away, but the queen shoots a venomous stinger missile that hits you in the back, immediately paralyzing you in your current position. The queen speaks to you, chastising you for your carelessness and offering to shoot you with the antidote only after her hive has been allowed to punish you. You can choose to either have 100 wasps sting you in your butt, or have 20 wasps sting you in your genitals (evenly divided between balls/penis or labia/clit).
I guess... butt? Both are not very tempting at all.

5. You are an Indiana Jones-type explorer searching for a treasure in an ancient temple. The treasure is a mystical orgasm ray that can cause anyone to immediately cum at any time by pointing it at their genitals and shooting. You reach the final room and see the treasure on a pedestal at the other end of the room. However, between you and the treasure is a deep, 30-meter (100-foot) long pool filled with pure urine. Do you swim across or give up/try to find another way?
I would swim across. After all my work to find this ancient artifact I would think that I could swim through a little pee.

Bonus: You're a Pokémon trainer in the Pokémon universe. A hot trainer of the opposite sex challenges you to a battle in the middle of a grassy field. Unfortunately your team doesn't do so well. As your last Pokémon is about to faint, your opponent's Venusaur blasts a load of sleep powder in your face, knocking you out. When you awaken you find yourself naked, your arms and legs bound and held apart spread-eagle by the Venusaur tightly gripping vines. Holding a video camera, your opponent laughs in your face and informs you that they're going to record you getting fucked by one of their Pokémon. The opponent's other Pokémon include a Charizard, Jolteon, Goodra, Lucario, and Houndoom, all of whom are the opposite sex of you. Pretending to be gracious, the opponent offers to let you choose which Pokémon to be raped by. Which one?
I pick Houndoom, It is kinda a fantasy of mine to have sex with a canine. (I would never act on it because I feel like it would be wrong to force one to do so. But that kinda makes the fantasy so much more of a turn on)