I think it's possible but not possible to know for sure. Again, Tenshinhan said it was a light swing, so Piccolo was playing regardless.
It's pure guesswork as to the gap between Yamcha and Roshi for the wind chop feat. It could be anything.
I think it could be closer to 2x, maybe less. DB has some good feats at small gaps.
I think the Ming Piccolo feat is probably the smallest gap wind chop feat. Others with successful chops could be anywhere from 2x to 10x and we can't really know.
1. It's entirely possible a full effort wind chop from Piccolo could knock Goku down.
2. Should be more than his old body power, so based on power levels it may be equivalent to about 70-80% of young full power Piccolo.
Yamcha doesn't seem to have an official power level in the first...
Tenshinhan says it's a "light swing". It's not a full effort swing clearly. I think you're putting too much stock into it. Piccolo doesn't even look like he's trying hard.
You thought this would mean that Piccolo can't wind chop Goku with that power gap, but that would be assuming Piccolo used...
At best a particularly strong human with trained "flicking" like a kung fu master who moonlights as a frying pan folder could leave a nasty welt on a toddler with a finger flick.
Vegeta's fights against 18 and Recoome could hold some insight. Vegeta was able to blow off Recoome's armor but couldn't blow off 18's clothes. Then again, could just be artistic license.
I don't have time to read this all but based on the initial premise it would be cool. Some games do this to a small degree. I would want a branching path story where depending on if you avoid canon events you can skew into the movies and back. Like if you visit Kame house in DBZ early you get...
That's fair, but I think Goku saying he's never felt such awesome ki before Baby Vegeta Strongest Form 2 means that before then there was a ki he had felt that was more awesome than initial/SSJ Baby Vegeta but less than SF2.
I think DBS has Goku tell Beerus he can't go any higher than SSJ3 in their first fight, so Daima having Goku keep SSJ4 seems to very clearly show a contradiction and probably a different timeline.
The only people who think it was retconned are those who don't like the implications of such a strong base Goku and Vegeta against other scenes like Goku vs Great Saiyaman Gohan and the Trio De Dangers vs Goku, Gohan, and Buu. It just means some scenes are just odd but in the face of the direct...