Explosion radius and damage will be capped at a certain point.
I hope that's partly what the SAM bar is used for. If you take away most of the damage and radius, I'd think most beam attacks could just be dodged at the last second with minor repercussions and never blocked, especially if people have 700 hp.
This way you can make normal KHH-like beam attacks capped, like you say, but also have one-time larger explosions that the opponent could be forced to block.
But this doesn't have much to do with noob-friendliness anymore does it? So I'll try to relate.
Like what everyone is saying, certain basics outside of the game must be mastered, such as mouse movement, to give an advantage. Then there's mechanics in the game that can be controlled to level it out, like limiting how much you can teleport at once.
Noobs don't spam teleport, only good players do, and they can do it really well. Noobs don't block, but good players can block almost every attack if they kite the opponent in their direction. EX: Falling, gliding, blocking from above. If teleporting too much drains stamina, and blocking too much reduces ki levels, then it would become easier to break their defense. So the stage is set for a more aggressive game instead of having a never-ending, flawless defense, which is what distinguishes a pro imo. Angle hits are great and all, but if your hits are evaded, blocked, or countered, then they don't matter. Turbo and block completely negates any damage done currently. So anyhow, noobs would only need to really get the hang of the aggressive end of the game to do well since they wouldn't be hitting a player and gaining no advantage constantly. If every hit did SOMETHING, like made the opponent even slightly less able to attack, then it would help. The charging of turbo will also play a factor in helping the aggressive side overpower the defensive side, I'm sure. So the idea would be that the best defense is a good offense?
The biggest curb stomp on noobs and any good player alike is the triple hit ki blast combo, which is essentially a way of saying, I got this one hit in, so now you're dead, and there's nothing you can do about it. When they gain power level at a faster rate from doing this to boot, it becomes more unbalanced and deadly. So since you've already added using stamina to recover quickly, there's no need to worry about that anymore, and that's the most important balance factor imo.
Same goes for spamming ki attacks, which is where that cap comes into play. The slower SAM bar progression against weaker opponents can prevent huge attacks against noobs who will always have the lower power level, regardless of how many hits they may score occasionally. Whereas two good players will have about the same PL, and the SAM bar will progress evenly.
This would also give a reason to fight in a lower state and THEN transform, so you could charge your SAM bar quicker or prevent the opponent from doing so, and then transform to unleash a deadly string of attacks and gain the upper-hand. It would distinguish certain advantages and playing styles based on temp-trans characters and permatrans. People who are all about the SAM bar might want to play SSJ. Players who are all about the actual game mechanics themselves and rely less so on it might want permatrans characters. A Frieza-type character that can gain advantages from transforming but gains less of a multiplier can have a little of both.
That's also why I think the SAM bar should be used for transformations as well, so that SSJ-type characters would NEED to have a certain SAM level before they can transform quickly, and that would be their disadvantage, whereas permatrans wouldn't need the SAM bar at all. Lets face it, a long transform in a fast-paced fighting match will just leave you open to get killed. So in this respect, without a transformation disadvantage, a temptrans character would have more diversity in how they choose to fight, where permatrans would seem limited in that respect since they're always maxed out.
Anyway, there's my long $#% post. I think you've already hammered the biggest imbalance out with the immediate recovery. I'm not sure if you've considered this SAM bar idea though. It sounds like a win-win to me. ^_^