This is true for pigeons also? is that correct? While hand raising one of the babies I survived on take-out. I was too scared to cook anything as I always use non-stick pans.
One or two birds would be fine in that cage as long as they had some time in a larger area for exercise on a regular basis.
@cavemanrich posted a pic of a portable outdoor aviary in another thread. He would just take them there for exercise periods. I just can't find it quickly. If you decide on outside living you could create a loft attached to the duckhouse as long as the pigeons have their own enclosure/aviary.
Some cats are predatory towards birds and some are not. Do yours hunt?