The outer door had a considerable leak, as the water rose quickly within a few minutes, yet after the sailor was removed and the door left open, no more water was shown leaking into the sub.
When the Captain orders Battle/Action stations no crewmen come into the torpedo room to man them, as they would in an alert.
There are several ways the torpedo tube door could be opened, such as bypassing the hydraulics, unbolting the lock, or as was briefly discussed cutting it open. It would not have been handled as shown. Similarly, the Captain's argument about a lack of readiness if the tube were damaged was moot, since with the door stuck they could not load anything into it anyway.
The USS Washington would NEVER use active sonar, especially in the situation they were in. Pinging sonar would give the NK Romeo sub the USS Washington's position. They would definitely know a US sub was operating in their waters. Submarines detect and track targets through passive sonar.
The order for all hands to man battle stations is given and Jason asks why the sailor stopped using the grinder. As a Master Chief, he would know a command to man battle stations would divert the crew from other functions.