"No. She is never beyond my grasp."
"But if she should reach the Senate..."
"She will never see the Senate again."
But if Maul just shows up on Tatooine, then the additional sub-plot will only weaken the already weak storyline.
Then we've got a runaway queen headed to god knows where who sends her handmaiden into town to "learn about the culture" as her people die, then they discover a slave boy who likes to "pod-race" (whatever that is), and they decide to pod-race to get the parts they need, then they realize the boy's a "vergence", and then some guy in black starts looking for them and by that time it's like, "where is this going and who the hell were those Trade Federation guys that were in this movie when it started?"
The best thing about Maul on Tatooine is that he can energize this slow, unrelated side-trip by representing the antagonists of the main story. If we don't know why he's there, then that's just one more thing we don't understand. The movie needs MORE structure, not less. Making him the outreaching claw of Gunray, threatening our heroes as they desperately try to get their ship going. That tension is what's sadly missing. We need ways to extend the impact Maul has throughout the Tatooine sequence -- ways to show those probe droids searching and just missing our heroes as they prepare for the race.
Obscuring the nature of Maul's threat does nothing to help that I can see. But maybe having him be the surprising method Gunray has for chasing Amidala down -- the fulfillment of a threat -- is an improvement.
If we just cut Maul from Tatooine altogether, then the Tatooine stuff becomes a complete side-show which we might as well cut altogether -- just have them swing by and pick up Anakin in a couple of brief scenes. Watoo sells them parts, and a slave. No pod-race and they get back on the road.
WIthout Maul, the Tatooine story has NOTHING to do with the main story.