Good points, but with regard to not going SS3 against Majin Vegeta, he could have one shotted him, but then he wanted to snap Vegeta out of his Majin ass, and it worked. Who knows what would have happened if he'd defeat Vegeta and he'd stay Majin. At least Goku knew that he could go SS3 in case Buu hatched in order to defeat Buu. Getting Vegeta back was his priority I guess. Goku always has been a talker "stop this, please stop etc." This is the theory from my ass.
I'm not saying he didn't do dumb things in Z, but it's not nearly on the same level as Super. He turned his back to Frieza... The dude that killed Krillin, fired an energy wave at Goku from behind him on Namek, tortured and nearly killed Gohan during RoF, and destroyed the Earth without hesitation. Then, after witnessing him murder the Goombas with his Omega beams, Goku still has the idea to turn his back to Frieza.
Then there is him hiring Hit to kill him. Then there is carelessness during the ToP arc. Like, it's in Goku's characters to actually be the cause of ToP, but once he's in a fight with that high if stakes, I don't remember him being that careless.