When Malcom goes to sickbay to test the lifeform's tolerance to E.M. fields he places a device on the observation window of the creature's enclosure. This device changes position at least once between shots during this scene.
When the creature gives what appears to be latitude and longitude coordinates for the planet that it wanted to be deposited on, there would be no way for Enterprise to determine the correct longitude, since the creature did not give a basis for the planet's prime meridian, or place on the planet designated as longitude 0.
Ensign Hoshi only mentions that the data appear to contain coordinates after translation/decoding, she never said that the data are plainly "latitude and longitude". It's never mentioned how much data Hoshi had to translate/decode and if that data also included information such as the "prime meridian" or not; and it may even be possible that the coordinates were given in a completely different mathematical frame of reference which doesn't use meridians at all.
Ensign Hoshi only mentions that the data appear to contain coordinates after translation/decoding, she never said that the data are plainly "latitude and longitude". It's never mentioned how much data Hoshi had to translate/decode and if that data also included information such as the "prime meridian" or not; and it may even be possible that the coordinates were given in a completely different mathematical frame of reference which doesn't use meridians at all.
When Archer and Tucker are captured by the life form, a fifth crewmen is taken in addition to the existing four named captives; Rostov, Kelly, Archer and Tucker. However, we never hear or see anything further about the anonymous crewman after this point.
When examining the part of the creature severed by the door, which is still alive, Dr. Phlox compares it to an earthworm. It is a misconception that if an earthworm is cut in half, both parts will survive. There is a chance the head section may survive, however, the tail end will die.
Captain Archer states that the water polo pool is deep enough that the players can't stand. In fact, a standard depth for a water polo pool is six feet. It is common for men's water polo teams to recruit players tall enough to stand in that depth.
When Crewman Kelly discovers Crewman Rostov trapped in the creature, she calls Captain Archer directly. Her correct action would be to call her superior, or perhaps to call for Security or Medical assistance, and not skip the chain of command.