Your scope shot shows that the ADIS16448 is responding exactly as it is specified. In the examples I provided, the code reads those signals correctly to capture the correct data. While I will try to take a look at your code, this is a MEMS support forum, not a forum where processor/firmware troubleshooting support is the intention. You might want to request support from your processor provider of you have a question on how it receives and processes data through its SPI-compatible interface.
With respect to the burst mode, it works exactly as described in the Datasheet. It is tested & verified, 100% before parts go to stock. If it were me, I woukd focus on making the single read sequence produce exactly what is expected before complicating matters with the burst. Perhaps the two are related.
ONE NOTE: You do not need a stall time between each 16-bit data sequence in the burst response. It doesn't hurt, but it is not required.