Actually, the rage boost is a trait exclusive to Gohan, not to Saiyan Halflings. Goten & Trunks never displayed rage boosts, neither did Bra in GT. Pan got rage boosts in GT, but it could be a trait inherited from Gohan.Saiga wrote:Or maybe it didn't happen against Cell because Vegeta isn't a half-Saiyan hybrid.
Now for Vegeta in BoG, I believe that what happened to Vegeta is what he theorized about Goku. Vegeta suspected that because Goku was fighting for others, he had gained a mysterious power (which I believe that is related with yuuki and/or shouki), which is why Vegeta couldn't keep up with him, since he was fighting for himself. Vegeta believed that this could be true, but wondered why he couldn't use that power now that he was also fighting for others (Bulma & Trunks). Now what I believe is that due to Vegeta's personality, he can only use that power momentarily, while for Goku, the effect of the power is passive, because of his personality. By fighting for others instead of yourself makes people unleash their true power IMO. And as for why Vegeta didn't use his true power when Trunks was killed, I believe this was because he wasn't a good guy yet like he was in Boo arc.
Besides, shouldn't Vegeta have larger amounts of dormant power compared to Goku? Vegeta was the son of the King, and had enormous power power from his childhood, while Goku was a low-class & born with very low power. Goku surpassed Vegeta because he drank the Super God Water, trained with the gods, and because he was a bigger fighting genius than Vegeta, not because he was born with such power (like Gohan).
All these make sense in my head, and makes things that doesn't makes sense making sense (lol). So, I'll go by these.





