Do male birds need to be able to reach the eggs to fertilize them?
Should I have an equal number of males and females? More females? More males?
If locking birds in 1x1 rooms and forbiding doors doesn't work. How do I keep my dwarves from harvesting the eggs?
Is egg production and bird breeding actually viable in this version? Or should I just butcher all these turkeys?
1. Yes. But you know that already.
2. Doesn't matter, you just need one pair that is able to breed. A single male can fertilize multiple batches. I seem to recall that some folks remarked that 3 of each sexual orientation give you pretty good chances of landing a breeding pair.
3. Eggs need to incubate, disturbed eggs won't hatch if mother is moved during incubation. You'll want to disable that
specific egg type from your food stockpile and just to be certain, go to the kitchens menu and disable cooking for that specific egg type, so cooks won't run in to the breeding room to grab eggs when they run out of ingredients to cook.
4. Egg production and breeding has been viable since last version and continues to be the same this version as far as I know. Only wrinkle in the process is that the changes to gender states make it more finicky to find a breeding pair (They both need to be heterosexual). Otherwise, everything else is the same.
Other things to note, hatching takes about a season or so, assuming they are fertilized. If they don't hatch for some reason or are unfertilized, you'll want to collect them so that the nest box can be freed for a new batch of eggs.
Overall, breeding animals is improved in my opinion, since you don't need to modify the raws to allow creatures without a [child] token to breed (Notably dragons). Do note that asexual reproduction is not yet enabled. So no Giant snail breeding without some raw modification. Good luck!