As for Raditz, He seems to be not an energy spammer like Vegeta (needless to say when Raditz did, it had devastating results).
After studying his attack pattern, he was more of a melee-rush fighter that specialized in counters.
This could be his base combo:
The Budokai Tenkaichi series had this moment as his rush attack:
Why can't FighterZ? The Raditz player can use it as a dash attack where the animation is like the anime where Raditz pops up behind the opponent and strikes them.
As for counters,
1)There is the infamous tail whip he did to Krillin (could be used as a bottom counter).
2) Kicking Goku
3) Goku grabbing his tail, but instead of begging the opponent to let him go (unless its Goku), Raditz turns and throws dirt in the opponent's face and blasts them.
How Raditz destroyed the Farmer's Truck.
Saturday Crush (a quick level 1 type finisher)
Double Sunday (shoots in the air then launches them at his opponent)
Support-wise there are possibilities
1) He could be used to catch energy attacks like he did to Goku's Kamehameha.
2) Appears and launch a Saturday Crush that paralyzes opponents momentarily like in the Xenoverse games.
3) Appear behind opponent and kicks them like he did to Goku