Okay, let's go with the basic Animated Actor concept used in such things as Who Framed Roger Rabbit and a number of Warner Bros. cartoons and films. Tom and Jerry are, at the start of the film, shooting a new short when all of a sudden the director, writer, and the rest of the crew just walk off the set. (The director is probably yelling at the writer "Okay, where's the rest of the script?!? What do you mean, you don't know what happens after the house gets demolished?").
Not knowing what to do, Tom and Jerry wander around the various sets of the studio, improvising silently, until they run into Pugsley. At this point, they realize they've walked into a different movie all of a sudden, so they humor Pugsley. They break character by talking and then singing with Pugsley about friendship. Afterwards, they attempt to find their way back to the set of the film they should be making, only to end up on the set of yet another film... a film about singing cat gangs.
Clearly spooked by this, they decide they were better off in the first wrong movie and rush back to that set, and meet Robyn. The director of that film says "Perfect! They're just who we need to play the sidekicks in this movie!" and casts them right away. Tom and Jerry accept, tired of being typecast and wanting to stretch themselves as actors.
At the film's end at Robyn's house, Tom and Jerry do a chase out of force of habit, and the director decides to just Throw It In! because it's a good nod to their normal stuff. And then he finds the unfinished short Tom and Jerry were filming before and slaps it on to the beginning of the movie, and tada! He's got Tom and Jerry: The Movie.
Everything from this point was just their Dying Dream as they lay buried under tons of rubble, a nightmare world in which they talk and are friends and their roles are reduced to sidekicks of a little girl, sort of a metaphor of the franchise dying with them...
- And, when they finally chase each other, they're trying to hold on to their last shreds of their previous forms before finally slipping into oblivion...
They're just so preoccupied with the chase that neither of them really bother speaking, except for those brief moments in the original shorts. Also, despite what fiction might tell you, high-speed chases don't really leave a lot of time for witty banter.
- This is well supported by the original shorts.
- The movie out-and-out says they always could, they just never had anything to say to each other.
Both are blonde, both were completely unnecessary additions that ruined the film of a beloved icon, and she did date Indiana Jones. The dark truth is that Willie and Indie broke up shortly after The Temple of Doom, but not before he unknowingly got her pregnant. Being the screamy, shallow whiner she is, Willie dumped Robyn in an orphanage. However, she had just enough human decency to give her a locket of her father, allowing her to locate him if she ever got into trouble.
Both Robyn and Tom's owner at the start of the movie are blonde. Tom and Jerry get amnesia from the wrecking ball during the demolition of the house. This allows Time Lords Puggsy and Frankie to send them back in time using what appears to be a Model T on cement blocks without them noticing. Off-screen experimentation by "Doctor" Applecheek gives Tom and Jerry the immortality needed to complete the time loop. As seen at the end of the movie, Tom and Jerry's destructive ways have eaten through Robyn's inheritance and forced her to sell "Robyn's nest" and move to the suburbs by the time the start of the movie happens again.
She didn't actually die, she just walked off on Robyn and her father to live for herself without them. To spare Robyn from the depressing truth, her dad said she died. She moved to the suburbs, became the owner of Tom and later, when Tom got lost during the move, she just decided 'Screw that cat'.
- He's just agreeing with Aunt Figg to avoid invoking her wrath. Notice how most of his parts in "Money is Such a Beautiful Word" are along the lines of "It is, it is" and "Quite so, quite so."
- Alternately, he had actual romantic feelings for her, and his responses in the song are his way of letting her know he'll give her what she wants if it'll make her happy with him.
Both are seemingly kind and harmless old men who appear to be giving the heroes their hearts' desires, but in reality, are nothing more than greedy opportunists who wish to exploit/sell animals for the right price. They even resemble each other: fat, round-faced, and even with thinning white/grey hair and a pug nose.