CCS/DRV8312-69M-KIT: max current

1. It's very tough for continuous running even the specs. of DRV812 shows it can support such current.
2. The maximum value 3.5-A continuous Phase Current (6.5-A Peak) if working in a good heating condition.

You might find more detailed information about the DRV812 power module as the following link
www.ti.com/.../DRV8312

For Q1&2, Just one point you need to pay attention to this kit, its peak-peak phase current is 6.5A, and continuous current is 3.5A in its datasheet. You should keep the phase current is less than both values. You can run the motor on this kit, but I don't think it can be worked well for a long time, the device maybe reports fault protection for over-heat. There is no problem if want to run your motor with this kit since DRV8312 has an integrated over-current and over-heat protection.
For Q3, sorry for confusing you, a cooling condition that means thermal dissipation of DRV8312. Please refer to the device's datasheet.