General strategy for these games is to force your opponent into unfavourable positions in order for them to burn ki and thus you can maintain the advantage in the fight. Mix-ups are generally an arrangement of using ki-blasts, strings which guard break, feinting guard break strings as some opponents will see it coming and react by side-stepping. Using supers during your opponents actions, like side-steps is also a decent idea with certain characters who have moves that can guard or armor break. Good pokes vary between all the characters. Typically characters like Broly and Piccolo are the best in this area purely due to their amazing range. But characters like Bardock who have armor on one of his cancel strings is typically great for a counter poke against character who have great range like Broly or Piccolo. Then it would be things like ki blasts for these characters as they won’t win against Bardock’s armor.
The start of the battle is always the most important part. Getting in there and making sure you can force a TC from your opponent will be the foundation of getting the lead in the battle. Once engaged I feel there aren’t really any more mindgames. The battles are fairly quick and there is rarely any downtime between the players fighting each other so it basically becomes what do I need to do to maintain a good ki advantage and do some decent damage.
There was a tier list on the DBC forums but I can’t really remember what it looks like now. I know Bardock is top tier because while he has a baseline ki of 3, he can dish out the most damage in the game. Omega Shenron was also up there because he has the highest baseline ki in the game and he is generally an amazing character with some good supers. I think Piccolo may have been up there also for his reach as well as just being a good character. I think Overlordtico knows more about the tier stuff.
My knowledge isn’t really as in-depth as some of the other players. I only got into the scene last year and I haven’t had much time to learn about what makes characters fall into which category with having University to do also. I’ve only really brushed up on some characters and I still don’t know about the majority of them. My knowledge of fighting games isn’t really the best either due to me not having the time to learn of such things. I have played some SSF4 and I’ve been to tournaments. So I can only tell you the things I have learnt while playing Budokai 3. People like Overlordtico or Saiyanjin2 are probably the guys to ask for further things about pokes, mix-ups, mindgames and the best way to approach opponents.
As far as I’m aware the capsule rules are basically use the breakthrough capsule on every character. Throws can be useful if you have a character that doesn’t really have any good pressuring strings which can guard break. It can also be useful to get an opponent off of you while they are pressuring you with strings. I’d say throws have about the same usefulness as they have in SSF4.