Just wanted to randomly toss in a neat-seeming possible tidbit.
In the technique name
Migatte no Goku'i, "Migatte" (身勝手 - "selfishness", but also
other stuff) happens to share a character with some Japanese words for victory - "Shōri" (勝利), as well as "Seishō" (制勝) and "Yūshō" (優勝). Taken alone, 勝 seems to be the character basically connoting the sense of "winning" common to these.
Now, I naturally have no idea whether Bardock actually uses one of these words for victory when he says that only an idiot would focus on anything other than victory in a life-or-death fight, or instead some other expression that lacks this character (e.g. "Bikutorī"), and it may be totally spurious or flawed or just plain irrelevant (
which would serve me right for stuffing bits of words from a language I don't understand into internet translators/dictionaries), but it seemed neat to me that the "secret of selfishness" might maybe have a little secret, as it were, tucked away within its own key word, which now seems relevant for the arc in general and (prospectively) for development of the technique's focus - so I thought I'd stick my neck out and share.
Re: Bardock and Gas guess-o-rama - Even if one says that Gas starts at 10,000 BP, moves up to around 20,000 and then to 60,000 (he says his level is beyond the limits of what Saiyans can do, and this was a figure proposed by Ginyu when the same basic consideration was in view with Goku), and Bardock starts at something like 1500 BP and makes his way up to (a performance level on par with, if not just actually) something like 75,000 just while he has the aura going on, I don't see that there's necessarily any difficulty. I mean, really, so long as they're both well below Freeza, and you're not wedded to the idea that Bardock's power is there at any other time than when he's actually 'doing the thing', you can really take your pick.