(1) Yes. Your group G is abelian, so what does conjugation do in G? (Remembering that Inn(G) is the set of automorphisms corresponding to conjugation).

For (2) you should realise that an automorphism is defined by where you send your generators to. As a hint, note that switching generators is an automorphism ( 3, 1)\mapsto (1, 3), (1, 3) \mapsto (3, 1)" alt="\phi3, 1)\mapsto (1, 3), (1, 3) \mapsto (3, 1)" /> is an automorphism).