When Archer wakes up in the past, as he rubs Porthos' ears, Porthos is curled up with his head to the left. As Archer walks away, Porthos is now curled up with his head to the right.
In Archer's private dining room during the teaser, he is very clearly pouring a clear liquid from the coffee pot into the three cups for him, Trip and T'Pol.
Considering the consequences of plasma interaction with their atmosphere there is no way they would ever allow anything that could remotely produce plasma (whatever it is in the Trek Universe) near their planet.
Daniels, the agent in charge of correcting time-line changes, early on in the episode says the explosion that destroys the colony (and is the basis for the entire episode's story-line) wasn't supposed to happen and is an incorrect time-line change. By the end of the end of the episode, Daniels had corrected every other time-line change except this one. He certainly would have corrected this and restored the colony and all the lives lost, which would conclude and resolve the incident.
When Archer and Tucker go into Daniels' locked room it is dark and no attempt to turn on the lights is made. While it could be assumed that power to the room had been cut since it was not in use, in Shockwave, Part II (2002) Reed goes into the same locked room and immediately turns on the light.