Goku aint fight Vegeta for humor
Let me break this down for you slow nikkas, at the start of the Boo saga, both Goku and Vegeta farly exceeded, Level 2, well when Vegeta saw Goku fight Yakon Vegeta seen Goku, give up all his Ki(light) well, knowing Level 2 limitations he seen Goku had gave the ki of what would have crashed a normal Level 2 with more to give and not sweating, Vegeta then knew Goku transformed another level, then Vegeta got mad and got under babidi control to force Goku to show his power or other form, Vegeta would have destroyed the earth, think about it even while whooping Goku ass he toyed with him, he wanted to see what's next..So its much deeper than to toy with Vegeta or to humor Goku, exactly why Vegeta koed him when he tried to fight buu, leave Vegeta alone
As far as Gohan, he wasn't in their ballpark during the buy saga, exactly why Vegeta shytted on him so