What I don't get is why Jigsaw wanted Hoffman to be tested yet again.
Hoffman hadn't been tested yet. Jigsaw's tape ( during the autopsy scene ) was clear in that regard, by saying "you think you would walk away untested
The message was clearly directed to Hoffman, though the coroner and the cops really didn't know that. So, Hoffman's real test was the bear trap that he managed to survive in Saw 6.
If I am understanding correctly, Jigsaw left Jill a list of people that still needed to be tested right? So she was in on it the whole time? Why did he leave her the reserve bear trap? Why did she use it on Hoffman at the end?
William was the only person to be tested ( other than Hoffman ). The people saved by William were either just victims or pawns during his game. You can argue the mother and the kid ( who actually was the one who killed William ) were being tested, but I guess they weren't really in real danger at all ( I mean, there was no consequence for them, after what happened to William ). So, I would ignore the mom and the kid ( and possibly the reporter ).
Those people were always meant to be kidnapped by Hoffman, because Jigsaw ( and obviously any person ) would know Jill wouldn't be able to set up William's game by getting all those people. Knowing that Hoffman has been working with Jigsaw for a long time, Jill obviously gave them the pics of the people, though she obviously didn't show Hoffman's own pic ( for game's reasons ). Jill was on it, but not directly. She knew what was going on, but she wasn't directly involved with the vitcims. She was involved with Hoffman's test, though.
I guess Jigsaw probably told Jill to wait for William's game until Hoffman could finally be tested. That's why she trapped Hoffman at the end of the movie ( and William's game ).
I would have shot Hoffman in the face, but the writers probably thought it was better giving Hoffman a reverse bear trap, lol. Yeah, Jill didn't have to do that ( Jigsaw was already dead ), but putting a bullet in Hoffman's skull would probably prevent Saw 7 from being made. So, I got why the writers went for the trap.
Was she mad that he blackmailed Amanda?
I wouldn't say Jill got mad because Hoffman blackmailed Amanda.
Hoffman's blackmail set up the events ( from Saw 3 ) that caused Jigsaw's death. Amanda was blackmailed by Hoffman's letter, leading her to lose control of her actions by
shooting the female doctor ( Lynn ), which lead the husband ( Jeff ) to kill her and kill Jigsaw for revenge, meaning the death of the doctor because her trap was linked to Jigsaw being alive.
So, Jill probably judged Hoffman for everything that happened and also for Jigsaw's death.
One could argue that maybe Jigsaw and Jill didn't know Amanda was with Cecil ( the drug addict ), but we'll never know for sure. Maybe they knew the whole time, and Amanda's real test would resist to Hoffman's letter and fight for her game. However, that would mean Jigsaw also could knew that Hoffman wrote that letter, which would have been confusing, because Jigsaw was the one who told Amanda to read that letter ( which had been written by Hoffman ). So, did Jigsaw write a different letter that got replaced by Hoffman's, or did he ask Hoffman to write that letter? We'll never know.
But that doesn't make sense because Amanda was semi responsible for killing her baby. Everything with Jill, the box, the bear trap and Hoffman doesn't add up. No spoilers for Saw 7 please.
Read my post above.
Why did Hoffman want Lynn killed?