The non-sensored micro motors are not the smoothest, but deadband really shouldn't be a problem.
I assume you are using the kit supplied motor also?
Firstly I'd set all of the ESC's settings to their most basic, so no timing advance etc.
Make sure that all of your trims and settings on your handset are set to neutral before you reset it too.
Have you double-checked that all of your connections are OK? particularly the 3 motor wires (one being dodgy may cause it to be 'sticky' which may be the issue)
Do you have any other radio gear that you can swap-out one piece at a time in order to pin-point the issue to a component????
Sorry its a bit basic, but basic is usually the best place to start with fault finding
