What Went Wrong
Man, this movie tried to pack it all in. Dark wizards, magical creatures, conflict between governments and the individual, romance, the tension between preserving wild beasts and keeping people safe. It feels like they didn’t think they had enough material for a single movie, so they stuffed it with extras to try to fill it out.
Unfortunately, they had enough material for at least three movies. Stuffing them all into the same film just squeezed them all so they couldn’t breathe.
But we can fix that.
How to Fix It
Break it up into three different movies.
There’s at least three plots I can see that could carry their own films. First, there’s Scamander and the gang searching for the fantastic beasts that escaped from his bag. Second (the least-fleshed-out plot), there’s Langdon Shaw (son of the newspaper man) and his attempts to impress his father with a big scoop. Finally, there’s Graves and his hunt for the obscurus’ host.
Each one of these could easily be their own movie. It would give us more time with all the characters, allow their relationships to deepen, and give more time to setup Graves as a friend that betrays Scamander and the gang, instead of leaning on “oh that’s Colin Farrell, he’s definitely the bad guy.”
So how would we fill out each of these plots, to make them a full movie?
The first plot doesn’t really need anything. Having Scamander come to New York and meet the other main characters while trying to re-capture his fantastic beasts is enough. This time, though, we make Graves a friend of the group, someone who understands them and argues with the President (who is the antagonist for this first film) for leniency.
Of course, Graves is only doing it because: a) he wants to use Scamander’s knowledge for his own ends, and b) the beasts in question are illegal, and anyone willing to break laws is a potential ally of his.
Also this way, we don’t have to have Kowalski lose all knowledge of Queenie. We can give them a proper happy ending, with them starting a secret romance.
The second plot needs the most filling out. We already have a hook to get it started, though: Scamander comes back to New York to hand-deliver his book to Tina. While there, they go to see a circus, where there just happens to be a magical creature that’s been captured. It’s on display as something other than it is, and everyone thinks it’s fake.
But: Shaw’s son suspects it might be real, and starts investigating. Meanwhile, Scamander and Tina are arguing because he wants to rescue the magical beast, while Tina (and her bosses) want to keep it under wraps, for fear of revealing magic to society at large.
Eventually, the creature escapes, forcing all four of the gang to join forces again to track it down and trap it before it causes so much damage that Shaw’s son gets his scoop. After they succeed, we get to see Scamander’s mass obliviate trick (just not the whole city, that’s ridiculous). Shaw’s son, frustrated and angry at being embarrassed in front of his father, stumbles upon the Second Salem group, who tell him what he’s come to suspect: witches live among us.
The third movie is the hunt for the obscurus. Scamander is again visiting Tina — maybe to ask her to marry him? — when Creedance’s powers start to spin out of control. This time, when Senator Shaw is murdered, we’ve got a lot more invested in the newspaper family, and Langdon’s step forward with the “solution” for his father will carry a lot more emotional weight.
We get the same climax, the same reveal of Graves as the villain, etc. But now we’ve spent three movies with all these characters, and everything that happens means more.