You also have to keep in mind though, that their most productive years will be their first few, and eggs will gradually decrease from then on. Not that you won't get eggs, just not the 6-7 you might get the first year or two.
As for inside only, it can be done, but they also will smell more like a barn than pigeons and exotic birds. Average max life would probably be about 10 years or so, or even longer. Most don't keep them that long and predators get them so it's hard to say really. I bet they would love outside time too if you could give that to them. You'll have to keep up on toe nails too since they are made to wear down in dirt scratching. Good luck on your venture!
As for inside only, it can be done, but they also will smell more like a barn than pigeons and exotic birds. Average max life would probably be about 10 years or so, or even longer. Most don't keep them that long and predators get them so it's hard to say really. I bet they would love outside time too if you could give that to them. You'll have to keep up on toe nails too since they are made to wear down in dirt scratching. Good luck on your venture!