1) Yes 2) The cable can be rated at 3A, thats fine (like the official google cable), but if it does not contain the proper resistors it will may attempt to draw >2.4A from your charger, which will have unknown results.
It is confusing to have A to C cables rated at 3A but still built to USB spec, so they will be limited to 2.4A in actual use. For now I'll stick with either the iOrange cable or others that advertise only 2.4A max charge.
I'm getting this one since the iOrange cables are starting to go out of stock on amazon.