Can I use a ST-LINK V2 as a universal JTAG or TTL serial interface?
First of all it is not an JTAG probe. It is the ARM SWD debugger probe. Probably you can use it with non STM32 ARM microcontrollers using openOCD. .

This probe does not have UART &lt;> USB converter you of course can't use it.  You need ST-LINK V2/1