2 questions about limesdr mini

My current SDR produces a lot of errors of type ooooooooooooooooooooooooooooo when I go over 7 mhz of sample rate,
as it has usb2 I think that may be why.
Could the limesdr mini solve this problem?

The second question is about the quality of the recordings-transmissions, my current sdr loses 3 or 4 db in the MER when recording and reproducing dvb-t signals (8 mhz). Could the limesdr improve this data?

Thank you