How Would Moro Arc Piccolo Fare In DBZ?

[Cipher]

The only other statement is Goku saying 17 is about on their level but that could have been a collective our for a team that included Kuririn Ten Piccolo etc.

There's a bit more to it than that. Goku finishes talking about how he wishes he could have beaten Jiren one on one, and is shocked by how strong he was. Beerus comments on the universe(s) being vast, and Goku then says it's not just other universes--#17 had about caught up to where they were and all he hadn't been doing anything special.

The line itself could be referring to the group as a whole, but in context it's fairly obvious Goku is talking about fighters around his own general level, as the beat starts on being surprised and inspired by Jiren.

It's only "around" though, not a hard "He's exactly as strong as we are!" But it's not hard to put two and two together with his more explicit power-up in the anime and his skirmish with SS3 Goku in the manga and guess that the intent across both versions was to have him be a Blue-(ish)-level fighter, along with Gohan. Somewhere up there, albeit not as strong as Goku and Vegeta themselves.

[BWri]

I doubt his intent to kill Moro inside that dome would actually do anything, Moro not only is GoD tier or something close to that, but could regenerate too.

Probably not, but Piccolo also knows how strong Moro, Goku, and Vegeta are and to assume his attack would do anything at all against Moro would mean he could amp it well past SSB levels since a direct SSB level attack would also have no affect on Moro. These guys are fighting leagues beyond where they were as SSBs during the U6 arc. Complete/Mastered SSB itself is leagues above SSB, like the difference between a solo fighter and a fusion. Vegeta also rose his power by several dimensions during the FT arc before mastering SSB. The power that's even needed to think you can hurt Moro at this point is astounding. And Piccolo is not some fool who makes pointless boasts. He doesn't even make moves unless he thinks there's some sort of success rate.

The thing is, if Piccolo can accomplish even 1,000,000th of what he intends, then he's already much stronger than what most give him credit for.

Besides he was charging up his Light Granade, I don't know what Jaco was talking about, he was about to do the same attack he did to 1st form Cell, perhaps Jaco was thinking that it'd be such a huge attack that getting stuck up with it inside the dome would be devastating but Moro can turn off the dome just like that. Even absorb it!

It looks just like LG, but Piccolo was also talking as if he was going to self destruct. LG is a forward facing attack so it's doubtful it would destroy anything that was not in front of Piccolo. Jaco makes the logical conclusion to Piccolo's statement. His statement of there being "nothing left in here when I'm done" doesn't seem to apply only to Moro because he's not directly addressing Moro. Seems he's talking about the area of effect of the attack which is contained in the barrier. I just chalked up the pose as Toyo wanting to use an iconic reference for the scene.

I think Moro's main concern was that attack obliterating his many meals lying around.

Could be, but he didn't say that, though I can see this. It still doesn't take away from Piccolo's assessment of his attack.