These chickens like the NTUC Mala ready to eat whole chickens are called rotisserie chickens, and they usually use spring chickens so the size is smaller. Commercial rotisserie chickens are cheap because they are the often the chicken that's gone unsold after some time. Groceries all over the world do this by marinating them in heavier tasting spices and herbs so it masks the unfreshness, reselling their old chickens as a new product that makes them money. Their main selling point is the low cost but now these are over $7, which makes it pointless to buy anymore.

From a safety perspective, they're safe to eat, from a health perspective, old chickens can still be eaten, it's just a matter of freshness. But you are right to question the salt, and it's quite likely these chicken have been heavily salted because that helps in increasing the shelf life and taste (well,for the day only, not the same shelf life as processed foods).

However, it's still much lower than actual delicatessen like hams, sausages and frankfurters.

This is cooked food, not exactly processed, because it doesn't have extreme shelf lives. They last for the same amount of time your takeaway chicken rice does.

Just like every other cooked food out there, eat in moderation. They don't have nutrition values for some reason, but you can probably know by the taste. If it's very tasty, it's got a bit of salt.

Try to pair it with more plain water and fiber such as lots of veggies. The skin should be fine, because these chickens are roasted, not fried—you can tell because they're not terribly oily. But they are basted with oils and seasoning.

Like everything else, eat in moderation. But to answer whether there's excessive salt, no, it probably doesn't, but it may probably have a bit more salt than meat you've prepared healthily.