Don't like Vegetas voice in Kai at all, and the dialogue is way worse.
For me the music in the first gives so much more emotion to the scenes than the original Japanese tracks.
If Goku's power level increases at the same rate till the end of DBGT as it does till the end of the Frieza saga, as a SS4 Goku would have a PL of roughly 939 Quinoctogintillion. For reference that is a 260 digit number. A PL of 14,600 is required to destroy an earth sized planet. There are about 2 nonillion earths worth of mass in the universe. That means SS4 Goku can destroy the universe about 32 Octosexagintillion times over. There's a reason they made Goku a god at the end of GT.
Anyway, I thought one of your theories as to why post-Namek fights never destroyed the planet after the first punch was that they were actively condensing their Ki to limit the damage to their opponent and any nearby rocks?
For example, Dodonpa is a high concentration of Ki in a form of a small beam, that is supposed to pierce it's targets, not blow them up.
Kamehameha on the other hand is also a high concentration of Ki in a form of a medium-sized beam, that is supposed to either push it's target away or completely anihilate it. It can also blow up moons as shown in original Dragon Ball series by Muten Roshi during Tenkaichi Tournament.
Final Flash - just like Kamehameha, but looks like it's the power of Super Saiyan form concentrated and fired as a monster-sized beam.
As to Ki releases on punches .....
There are 2 possibilities:
1) They are using Ki to accelerate the speed of their punches and to reinforce their body, which leads to increased power ..... something like releasing it from the back of their hands to accelerate ?
2) They are using Ki to directly increase the damage of their punches of their fists and to reinforce their body ..... releasing it from the front in a form of small explosions ?
Was it ever explained HOW they are using their Ki to increase their power ? I do remember Piccolo talking about that to android Dr. Gero or Cell, but if memory serves me well it was along the line of "we release our Ki in short bursts to increase our power" ..... or something like that.