Jon Thompson:

I think what you wrote in your 4th point is what Saw 5 will be all about. The ending to Saw 4 insinuates that.

I very much agree with your 1st and 2nd point. That was kinda annoying.

(SPOILER)I think you're wrong about Saw 3 and 4 not happening at the same time. I think Jeff being shot and the FBI agent being locked up in the room is chronologically the last thing to happen, except from the autopsy room. I think the story will pick up from there and we'll see what happens to the guy locked up in the room Jeff & Lynn died. What happens between he got locked up and the police came and discovered this place is what I think we'll also find out in Saw 5. As well as what Hoffman's task is, which was inside Jigsaw's stomach.

I liked Saw 4 much better than Saw 3. Better story, less unnecessary gore, and a better twist at the end.