I also just recently saw it for the first time, and am not having much trouble with the nested dream concept ...but do have a couple of questions:

Did Michael Caine's character believe that Dom had killed Mal? (I think he did not believe it, but Mrs., uh, Pennyworth might well have... hence Dom's parents-in-law not dragging the grandkids to whatever country Dom could set up shop in).

Did Saito not have an opinion about whether Dom was a murderer, or did he just not care about potentially putting Dom's kids into danger? (I have a bit more of a problem with this one. Saito seemed to research his business associates pretty thoroughly, but I have difficulty believing that Saito would have more data on this than, say, Arthur had).

I look forward to my next viewing of the film :>