ae86
1. the detection is not the best but it should be working. I have mine set for Motion Alert: the camera records continuously but when motion is detected a 6 seconds clip is uploaded to the Chinese servers and is accessible by phone app. You also most of the time get an notification on the phone.
2. This is how it works by default, exactly like a dashcam. The other option if I remember correctly is to set it up to record only when motion is detected.
3. the files are saved on the SD card. You can access all the files [not really see the files, but you browse back the footage] from the phone app or just take the SD out and connect it to PC or phone.
For extensive info related firmware/bugs/hacks see this forum with Google translate:
http://4pda.ru/forum/index.php?showtopic=638230&st=10060