The cage items are not ok if you want to have healthy babies. The wheel is not safe for many reasons. The first of which is because the kits tend to crawl under or behind the wheel and if mom runs on the wheel while they are in those positions, it could kill them. This has happened too many times when people don't see the wheel as a potential hazard to small kits. Another reason is because the kits should not be running on the wheel. Growing chinchillas need all their energy to grow and kits with wheels have been known to suffer from hypoglycemia and die.
Ledges are unsafe, not for the kits crawling up and falling because they do that no matter the size of your cage or lack of ledges and it is a scary thing to see. If the ledges are too high, the mother will climb on them and ignore her kits or could jump off the ledge, landing on a baby and killing them. The jumping off the ledge occurs more in litters of multiples because the mother might not notice one baby while talking to another and jump down onto the unnoticed baby.
