Is there any way that, by looking at a bit stream, for me to know if I'm using the right bitrate?
or whether the bits are inverted,
Is this RS232 or 5v logic signal?Measure the voltage during the 32sec idle period to determine the polarity. That will remove one variable.
This unit sends a short data burst about every 32 seconds.
So the question is, who or what sends it?
The module has a signal strength indicator, so you can use it to detect the sender? (neighbour, TV, elektricity meter, washing machine ...?)
The 9600baud looks most promissing, but still makes little sense - is 19200 and 38k4 log also possible?
No pattern, looks mess before and after - bit-rate is wrong.