Questions about Ugreen Car adapter

You can switch back and forth, but you can't fast-forward or rewind within a track (song). At least not for me.

Unfortunately, I don't know. I only used it for the car because the car had no Bluetooth connection. I only remember that the adapter had to be charged very often. Otherwise I was satisfied.

No, unfortunately you cannot use and charge the device at the same time. I have tried.