Why is RCN less basic than RNH2?

#1

In rcn N is sp hybridized and in rnh2 n is sp3 hybridized which means rcn should be more elctronegative than rnh2 as sp hybridization is more electronegative than sp3 so rcn should be more basic than rnh2

#2

#3

Why will RCN take H from carbon and not water?

#4

+ve charge on nitrogen with triple bond is highly unstable.