A:AnswerThe Alexa devices such as the Echo and Echo dot come pre-packaged with the power block and cord in the box.
The Power Block and the cords are White. Do not believe a Black cord is available.
A:AnswerYes. Any alexa device can be used as a chime for the ring doorbell. Here's a link to a video on how to set up the dot as a chime. https://www.youtube.com/watch?v=jrJ40b3uYbQ
A:AnswerNo. Just the premium dot 4.
But even though the 4th-gen Echo Dot gives you the requisite voice control, and those compatible devices will appear in your Alexa app, the full-sized Echo is the only one of this pair that includes an integrated wireless control hub.