Just another guess at something to try. I do get answers from the radio at certain port settings but nothing that matches what I expect. I tried big endian, little endian, swapped bytes, and got nothing intelligible.
You're writing a byte stream to the serial port; endianess is not an issue here.
The code you sent shows a baudrate setting of 38400. I don't know of any other radios in that class that use such a high rate. Can I assume that it's just a result of you trying things? Your trace from the OEM software should clearly indicate what rate to use, and I'd expect that it should be 9600.
I used gtkterm and got similar junk. The responses do not make sense.
Are you seeing your own echo? Are you doing a binary upload or something in order to get the \x02 and timing correct?
Perhaps you could go back to the rate you learned from the OEM software and then run what you sent us against the radio and send us the console output?
The only thing I noticed is that under Linux the radio blinks its display on chirp startup whether or not the radio is on. It does not do that under windows.
That's just a toggling of the port lines, probably DTR.