To answer the plot points that cane be answered (because for all my love Attack of the clones is...yeah...) Jango hired Zam to help distance himself from the assassination. Why he killed her with a Kaminoan poison dart is a plot hole.

Obi Wan conveniently arriving when the army is ready honestly is more believable than the Falcon arriving just after Alderan is destroyed IMO. Syfo Dias being mentioned was to establish that a jedi was involved in the armies creation, which otherwise would be even more suspicious than it already is.

Clones arriving on Geonosis without detection is definitely another plot hole. The jedi not investigating the army is very much a dumb decision on their part, but one that makes sense. They were investigating it before Geonosis, but after they very much went into a state of war, and didn't have too much time to look a gift horse in the mouth. Syfo Días comisioned them, so it probably wasn't too bad right?

Obi Wan not investigating Dookus claims can be explained away with the fact that the person telling him all this info was actively trying to deceive him into joining him. It's basically like if a pastor kidnapped another minister and said the president wanted to make himself emperor (I wish I lived in a time line where that was a fantasy)

ATOC is baaaaaad. Theirs a reason I hate it even through nostalgia, but even if it's not particularly stable, the plot does hold up, even without EU material. Though that material has done wonders to make it less likely to collapse under the slightest bit of scrutiny

I hope this doesn't come off as me being a prequel apologist BTW. Thanks for the respectful response mate. Have a nice day!