Yes
Yes
No
You will get all sorts of differing views on dash cams. People say they are bad because people are non stop reporting others for wanky driving etc. Long and short I'd rather have one if needed than not have one and loose an insurance claim etc.
I have them in my cars, £14 off ebay and a 32gb card to fit. Work brilliantly, auto start on ignition and turn off, does what it says on the tin. Super duper