no, none of them do.
All amphibians have tongues but not all use it for eating.
Yes, newts are amphibians.
All amphibians have backbones. An animal with a backbone is called a vertebrate. All amphibians are vertebrates.
All salamanders are amphibians.
No, amphibians are their own species.
Yes, all amphibians have backbones.
Yes, all frogs are. All frogs are amphibians.
No only reptiles. Amphibians have moist permeable skin.
Yes. All frogs are amphibians.
Yes, there are no producer or parasitic amphibians.
No, amphibians do not need to have there skin wet at all times. Most amphibians can be in and out of water.
Yes, they do. All amphibians are vertebrates, so they have backbones.