No USB power adapter, just cable 

Yes, it comes with a mount which is a plastic pipe with a pivot at the base. I'm sure you could mount the station itself on the same size pipe. The hardest thing would be getting it level. I'm not sure what diameter the pipe is but I would guess the outside diameter is around 1 in. The pipe in the picture is part of the base, and the unit sits over the end of the pipe. Hope this answers your question. 

Yes, this portable carbon monoxide detector has a hole on the top, so we can use lanyard to hang it to the wall 

Has a 1/4 threaded connection for use with a tripod 

No, you can't sync two of these to use.