Are there any other options to setting the sensitivity? as i seem to be stuck between the front folding or it springs back that fast that it flips over the opposite direction, also while i was writing this the game closed down it does this a few times, cheers for any help.
Try the direct lean option in the 'input' menus, (slider on bottom left) reducing that value can help bike springing back.
(I run about 65% on xbox one controller)
Alternatively, if you go onto the inputs, the sliders on the top right are useful for manually adjusting each input axis properties, just use the drop down to edit the axis you want (lean in this case), and then drag the sliders.
There is no right or wrong values for these, it's personal preference, so just drag the sliders and find what you feel is best.
As for the game shutting down randomly, I believe if you right click the 'core' program, go to:
Properties - Compatibility - and set this to run in compatibility mode for Windows 8, and then run as admin, it should fix most crashing issues.
Hope this helps