A:AnswerYes it can. There are many different faces, and there is an app that allows you to create your own face with those options and a picture of your own choosing.
A:AnswerThat's what I have, and it works great. I think you just need to have the latest update for the phone, and the gear will update also when you sync.
A:AnswerYes. I had a galaxy gear connected to my galaxy note 2. No issues. Ultimately went with the Pebble smart watch though... For smart watches it's all about the battery life.