How to C

https://matt.sh/howto-c

Very good read for anyone that wants to write this outdated language in 2016.

>>16

solid reasons for using char/int/unsigned

What are they?
char is always obviously u8
int is always at least 16 bits (so use uint_fast16_t for loops) and you'd be insane to say you wanted different behaviour on 32/64 bit platforms
unsigned should be default because it is far more likely what you want, and you should "opt-in" to the slightly different behaviour of some signed operations, e.g. mod/div/rem/quotient

>>20

char is always obviously u8

No it's not, the signedness of char is implementation defined.