Is rotisserie chicken healthy?

Unless stated otherwise, most rotisserie chickens are too high in sodium due to the marinades and rubs used on it. Taking off the skin will not help much, because the cooking method lets the salt release into the meat underneath so you would get the effects of whatever was used before and during the cooking process. Better to look for items that are clearly marked, LOW sodium or low salt.

Yes, these are usually brined as a preservative and the sodium is much higher even if you remove the skin. Best to prepare it yourself at home. That way, you can remove the skin and there will be little salt affecting the meat.

At my grocery store. some chickens are cooked without salt and are so labeled. Choose those.

why would it be salty. its not cooked with anything added

The chicken itself has little salt. The salt would be on the skin, and most producers of ready-to-eat rotisserie chickens marinate and season the heck out of the skin. If you remove the skin, it won't be bad.

boil your chicken.

Check the nutrition label

If you remove the skin, the meat underneath should be fine

The skin usually has a lot of seasoning