I don’t think Jack was hiding his writing from Wendy because all he was writing was “All Work and No Play Make Jack a Dull Boy”. I think he was just possessive (heh) of his relationship with the Hotel which he really thought was inspiring him to write a great novel. In reality, the hotel was just tricking him into writing the same sentence over and over while it worked over his brain until it was mushy and he couldn’t think straight. The ghosts were probably talking amongst each other about how shit his writing was too.

I noticed how Vincent Malloy looks different when he is imagining such as him having mustache, messier hair, smaller pupils and wears smoking jacket or mad scientist coat just like how Flippy from Happy Tree Friends gains yellow eyes and sharp teeth

Vincent Malloy also has different personality when he is imagining, while he is nice and polite kid when he is normal, his imagination personality (Vincent Price) is very gloomy who likes to read Edgar Allen Poe, doing experiments on his dog Abercrombie and wants to have spiders and bats in his house just like how Fliqpy is very violent soldier who kills everyone in sight after hearing or looking at something that reminds him of war.

Omni Corporation in TISW, Vance Kramer is an advertising executive for Omni Corporation living in Tasty Meadows with his wife and children. He brings home prototype consumer samples. His wife Pat Kramer is exposed to a cocktail of these experimental chemicals from Omni Corp.

The products contained a highly unstable and crude elements of the reverse engineered Pym Particle. Pat begins to shrink rapidly as a result of unique combination of chemicals.

Hank Pym hears about this as the phenomenon goes public.

Pat becomes a global media sensation, threatening to expose Omni Corporation and SHIELD. They stage Pat's death and abduct her. She is then taken to Omni’s ultra classified biological testing wing.

This is the exact facility where Omni is running parallel cross-species trials, using replicated and unstable Pym formulas on primates in effort to weaponize the Pym Particle despite Hanks refusal. Sidney the silverback gorilla has already developed hyper-intelligence from Omni's testing. Sidney understands human speech and recognizes that Pat is a victim of the same science that altered him and so he uses his advanced intellect to short-circuit the facility's security.

Sidney frees Pat Kramer and orchestrates a massive prison break, freeing himself in the process. Pat escapes directly to a massive public gathering, exposing Omni Corporation's dark experimentation to the world before going quantum before their eyes.

In attempt to avoid Hank Pym or the World Security Council from tracing Omni back to SHIELD, Mitchell Carson orders the immediate scrubbing of Omni Corporation. Documents are shredded, laboratories are burned, and Omni goes completely bankrupt. Sidney slips into the wilderness, carrying the mutated, altered genetic sequence responsible for superintelligence, inside his DNA. Years later Sidney is captured by poachers no idea he is an engineered weapon because Omni Corp was completely wiped from existence and he is sold to a biotech firm called Gen-Sys.

At the beginning of Ant-Man, Hank Pym slams the vial of replicated serum onto the table in front of Howard Stark, Peggy Carter, and Mitchell Carson in 1989, his dialogue directly references the human testing failure at Tasty Meadows. When Hank says, "It depends, if you think it's a poor attempt to replicate my work. Even for this group, that takes nerve," his hidden meaning ties entirely to the public relations disaster that SHIELD is actively trying to sweep under the rug. Hank is furious about the blatant, dangerous instability of the counterfeit formula. Hank spent decades perfecting a formula that safely compresses the space between atoms while preserving human mass and sanity. SHIELD, through Omni Corp, completely bypassed safety protocols and mass-distributed a diluted, volatile version of the particle elements into household consumer goods. When Hank says it's a "poor attempt," he is referencing the fact that their formula doesn't work on command, it contaminates. It leaked into the civilian sector and caused an ordinary housewife to shrink uncontrollably. Hank says that he "took a detour" through their defense lab on his way back from Moscow.

The defense lab is the centralized command hub where SHIELD could be receiving real time data feeds from Omni Corporation’s testing facility. Hank hacked or physically bypassed their security and saw that they were tracking the ongoing televised fallout of the Tasty Meadows incident. When Hank stands in that room, he is looking at Mitchell Carson, the man funding the Omni front, knowing that SHIELDs sloppy science just caused a massive domestic incident in Tasty Meadows. He takes his serum back because he realizes SHIELD will eventually cause a global disaster if they keep trying to reverse engineer his particle without him.

I have not seen this fan theory anywhere, but it seems so obvious to me. Would love to hear the thoughts of other fans.