[Observer]

1. Make the Xindi arc last only about 3 episodes. That whole season really dragged.

2. Make more of the Romulan and Klingon threats.

3. Get rid of that awful last episode, or at least tell it from Archer's crew's point of view, focusing more on the signing of the Federaton Charter.

4. Don't kill Trip.

for a start.

[horatio]

2, 3 and 4 would have happened, respectively not happened if the show had not been prematurely canceled.

[Red Tsar]

I would have knocked off Trip and kept his clone on the crew. The clone was way more appealing a character.