A few weeks of not eating are not a big deal. I have actually heard of adult ball's, in good health going 4-5 months without a meal. Separation is a must. Probably be better if you could get them into totally separated cages and not just separate the cage, because boy will smell girl. Make sure you read through the care sheets again on the temps and humidity needs. I always say this so I'll say it again.
Yes, aquariums are good for seeing them, other than that, they stink. They don't hold temp, they don't hold humidity. I agree that covering 3 of the fours sides with dark paper is good, and then I'd back that with cardboard if your temps are iffy. I'd also cover 1/2 -2/3 of the top with foil covered cardboard to help maintain humidity.