Need Help With Two Problems Regarding Midi Mappings

Hi,

i got two problems with Midi mappings:

1.)
if i map a slider to my Behringer BCR2000 (7bit absolute), the midi cc values go from 0 to 127. the value 63 results in 49.606% and the value 64 in 50.394%. i wonder, if and how it is possible to set the mapped slider exactly to 50%.

2.)
if i set a knob on the BCR2000 to 14bit absolute (on channel 1, cc 1), the auto learn function from the renoise midi mapping behaves very strange: the type is recognized as 7bit abs and the cc no. is recognized as 33, even though it should be 1.
then, if i set the type manually to 14bit abs and the cc no. to 1, the knob moves changes the slider values but the maximum value of 16383 results only in a slider value of 0.775%. what’s that?!

thanks for your help…