Good job getting the video posted, and yes a 4GB card will be fine for the radio. Do the simplest thing first, you were so close to doing it, so try this now. Stay away from OpenTX unless we find you need to be upgraded.
Go into the Model Diatone C and scroll down to the Internal RF and hit enter and see what you have beside ACCESS, it should also have D16. Does it?
If so, set to D16 and hit enter so that it isn't flashing anymore, and then try the Bind procedure.
If you get it set to D16, then look where it says [RNG] will change to [BND] or [BIND]
Highlight that and press enter, if you do it correctly the radio will chirp every few seconds.
If all that is acting like it should then hold the bind button on the RX and power up the quad.
That should be it, unplug the quad and press enter on the radio again to get OUT bind mode and the chirping will stop.
If all that works properly, the next time you power up the quad, the R-XSR board will have a solid green light.