For me, "paying off the PT" means more about the themes than name-dropping, though I'll grant you the oddness of the podracing thing. I'm not quite sure that it entails precisely your assessment, though, since the marketing did have the reference while the final product did not. Oddly.
What themes are these? Honest question. There's something about learning from past failures, but...what have the new generation improved on so far? They're fighting the same battles, in the same ships, using the same tactics and ideologies.
'Don't rely on the Jedi?' But before, Obi and Yoda went into hiding, and a Resistance formed anyway. That's not a thing.
'Arms dealers perpetuate the cycle' But they were manipulated into that by Sidious in the PT, the TF would have preferred not to have a giant war.
And the New Republic demilitarised, yet the FO is just fine.
The podracing is significant in that there was no plausible excuse for it, and the idea that JJ is talking about 'coming up with our own stuff' as an excuse is interesting given TFA, which is built on wall to wall, lovingly lingering shots on random OT references like blue milk, the remote, the chess game thing, and so on. But a tiny inconsequential PT reference most people won't even notice is cut out, because 'Ew, PT', which is not a great attitude to have for the director of episode seven of a series.
As for what could have been done with Watto, I don't buy that there was literally nothing that could be done. If the Empire could be rebeled against and the First Order resisted, this one little shitstain slaveowner -- or even all of them on that dustbin world -- could have been addressed.
Could something have gone wrong? Well, of course. Doing nothing kind of guarantees an already going wrong thing continued going wrong, though, does it not?
Could something have been done? Maybe. Could something have been done without Schmi exploding? Less likely, but possible. Is it a positive outcome to kill Watto if the result is both him and Schmi dead? How does Anakin feel about that? Should you free a slave if it kills them?
What's your stance on Rose and Finn leaving the slave children behind on Canto Bight? I just assumed they had those same transmitter things to make sense of it. Rose knows about this stuff, it seems to be common knowledge. But the New Republic hasn't done anything, the Resistance hasn't done anything. And our leads apparently haven't done anything all this time.
The larger point still remains that Qui Gon not freeing Schmi has nothing to do with the Jedi rules, but Jedi rules keep being blamed for some reason. Which is one of the ways I think TCW departs from the PT's themes.
And as I said before, people in the act of rebelling/resistancing do not spontaneously materialize.
Thus -- especially in a context of the kind of weaponry dotting this setting -- they can most certainly be wiped out down to near-zero numbers at another given moment in time.
Well, they, uh, kinda do?
Here's how this kind of thing tends to happen (I've been reading about Leningrad this week, if that helps, I'm not just making this up)
Resistance group exists.
Authorities crack down brutally, decimate or destroy them.
The populace is disgusted by the authorities methods, and more resistance happens as a result.
And previously, the SW universe lined up with this. That's what Leia's line is about.
Even back in Naboo in TPM, after the queen disapeared, there was an independent resistance they were able to link up with when they returned. Padme wasn't running it, it just happened.
That's why oppressive regimes can never completely kill resistance, even if they can wipe out specific organisations.
But at this point I remember that it's one line in a trailer that may not mean anything at all. Let's wait and see, shall we?