Kyos Dad is not in the original 94 game as a player his just their to make Kyo go into rage mode and be able to beat Rugal, you know the whole my fathers been beaten to death thing, Im going to kill you for that!!
His in 95 as a sub boss, which includes him in the plot more, 95 is the start of the Orochi saga so says SNK and what they say goes.
Ok this Ryu and Ken issue always pops up, I know people were angry when CVS2 cameout and Terry didnt have a Intro with Ryu.
It terms of characters in their respective plots yes Ryu and Terry are equals.
However clearly the designs of Terry and Ken match more closely and I luv that little hat intro.
I never pick Ryo much and havent played for awhile but I think him and Ryu do have a special Intro, where Ryu acknowledges him by doing a Kyokugen style stance.
Kyo is simply the leading hero in SNKs leading franchise so I can understand why they did that.