You should probably just leave the eggs in the bucket tomorrow - they'll probably be safe there. When you have more time for nest-tending, you could try taking JJ out of the cage so she can go in the nestbox without interference from him. If she's already in the nest when he enters the cage, he might not mind. But stand by with a small towel in your hand so you can grab him if he gets violent.

I have a foster parent trio consisting of Vlad and the two hens who are in love with him, Snowy and Mims. After the babies hatch he's super protective of the nest, and attacks me viciously if I just put my hand in the cage to deliver food. So I dangle a hand towel in front of him, and when he attacks the towel I grab him with it, then put him in the bird room still wrapped in the towel so he can fight his way out of it. He wins the battle with the towel every time and is so pleased with his victory that he doesn't notice that he's losing the war lol. Now for the part that's relevant to you: he will also attack his mates sometimes (especially Mims) if they have been out of the cage and re-enter it while he's in there. I have to grab him with the towel so he can't hurt them, and not let him back in the cage until the hen has entered the nestbox. Once they're in the nestbox he's fine with it, and he's also OK if they're in the cage but not in the nestbox if he's been out of the cage voluntarily then comes back in. Cockatiels are weird sometimes.

Pippin was not on the nest this morning. No idea how long she was off; the eggs felt maybe a bit warmer than air temperature? Veins still pink when I candled, but my penlight isn't strong enough to show movement, if there was any. My brother was doing laundry late (the laundry room is right next to the birds), so that might have spooked her. She went right back on when the lights went on.

This whole egg business is stressful!

All you can do is wait and see. Red veins are a good sign that the eggs are still alive, but brown would be a bad sign. Hopefully they'll get settled in the nestbox soon - they'll feel more sheltered in there and will probably be less prone to spooking.

Candled again tonight, both eggs still have thick red veins so I guess Pippin wasn't off them long this morning. My (adult) cousins were over and playing with the birds for a bit, which the birds seemed to enjoy. Tomorrow we try about moving the nest again

The air sac in one of the eggs is large and tilted (it looks like the 'draw down' pictures for when an egg is about to hatch). I'm assuming the humidity is low because they're still on paper, but that shouldn't be a problem until the end of incubation? Or could that point to something else being wrong? Not that I can really do anything about it, but I'm curious.

It's normal for the air cell and veins to tilt to the side where the heat is. If they don't accept the nest box, switch the cup-like-nest and give them a shallow bowl with proper shavings for the nest. Here is a sticky on nest box and nest box shavings. http://www.littlefeatheredbuddies.com/i ... boxes.html
What's the humidity like in your house? It would help if you can let the birds wet their bums so they can bring humid to their eggs. If they get used to the nest box, you can most the walls of the box to bring humid. Just try not to overdue it or else the chick will drown in the egg. It's normal for the air cell to get bigger later on the incubating stage. Eggs start out with very small air cells but they grow as time goes by. Just make sure it doesn't get too big because like you said, it means they are low in humid which is a huge cause of DIS (dead in shell)

Do you know when the eggs were laid? Is it possible that it's getting ready to hatch?

I didn't keep track of the exact lay date, since originally it wasn't important. I'm going to guess one was laid around the 12th, and the other the 14th or 15th. They didn't start really sitting tight until the last egg either, although they'd hop on the nest a bit. They're not close to hatching; when I candle them they look close to the 8- or 10-day development on srtiel's website.

Not quite sure what the humidity is. The humidity outside is currently about 80% (yay oncoming thunderstorms), though the house isn't as bad--the hygrometer in my lizard's tank shows at 55%, which sounds about right for a house in MN. They've got a little bathtub and they've both been splashing in it a lot more than normal.

I looked back at srtiel's photo gallery and noticed that some of her early egg candles are tilted like this egg is.

I tried to switch the bedding in the bucket once already; Pippin was not happy. She'd sit for a minute, get up, sit, get up, sit, get up, wander around the cage...I think she was confused.

Can you take a picture of the egg being candles? I have some experience on egg development since I candled my bird eggs daily because I was too excited (yes, I know, you have a freak member by the username of Haimovfids) but it was just so tempting to see how much they changed on one night.

Also, as hatching time slowly gets closer, you will notice that the red veins will fade and the egg will get dark because that's where the chick is.

It sounds like low humidity isn't a problem for your eggs! Baruch is probably more experienced at candling than I am lol. It's good that you're candling and comparing it with Susanne's collages. If it looks normal compared to hers you're probably good. If it looks like the egg has lost too much moisture you can check for tiny cracks and repair any that you find. This link: http://www.brinsea.com/pdffiles/Brinsea_Handbook.pdf is mostly about artificial incubation, but it includes some info on what the air cell should be doing.

The link also has info on micro-managing the water content of the eggs and calculating what the current weight should be. Cockatiel eggs don't weigh much to start out with so you'd probably need a digital scale that weighs in hundredths of grams to really do it right, but tenths of grams would probably give you a fairly good idea if you wanted some math exercise. But you're probably better off to just keep the humidity at a reasonable level and let nature take its course. Anything that you calculated wouldn't necessarily be accurate, and it might cause useless anxiety instead of providing reassurance.