Also, Goku tells Piccolo that even if he could've won that he shouldn't. Why lie? It's not like he was hiding anything from Piccolo, he already flat out told him that he shouldn't. You keep coming up with weak reasons to hate on Goku. While it doesn't change the story that was written, it does give a good reason why Goku's inconsistent. It's because the writer was being inconsistent.
He wasn't really lying, he was just dodging the question to make one option seem more preferable.
Or it's just bad writing.
If you think that, then it's unnecessary bad writing, because the story never required Goku to have SS3.
Nope, Goku could defeat Piccolo
Barley, after getting his guts blasted through his chest, and only avoided death thanks to a nearby senzu dispenser. He could still very well lose if Piccolo's training gains outstrip his (which they would have, if Raditz didn't arrive) or just takes him by surprise. Also, there's absolutely nothing Goku could do if Piccolo decided to just wipe out all life on the planet with one attack.
and he was going to do his damnedest to win against Vegeta who couldn't fight back at that time
He simply couldn't beat Vegeta, he won purely by dumb luck and help the last time. Without it, or hell, even with it, Vegeta kills them all.
Goku at least had the advantage of being on Earth whereas Vegeta needed travel, get healed, and then travel back
...and then nuke the planet from orbit. Like he was going to do until he heard Freeza was heading for Namek.
Goku's also a very good fighter and with the knowledge of how strong Vegeta is, he has a good idea of what it would take to defeat him. Case in point, his gravity training increases his power far and above Vegeta's when he gets to Namek.
He does that by abusing zenkais, and Vegeta does the same thing. He also didn't know about that at the time he spared Vegeta.
He knows what it takes to defeat him, so he should know they can't actually do it.
I'm not arguing he made great choices but it's not the same thing as he did with Buu. How is this the same? You have yet to answer that question. Goku always intended to fight those enemies. YOu don't answer that, and seemingly evade that because I don't think you have an answer.
I don't need an answer. I have Toriyama telling us "this is what Goku is like". YOU have nothing. I'm just pointing out that Goku being a selfish asshole who the universe bends to just so his dumb actions don't get everyone killed is nothing new.