Tempo

Slow Down (Slow)

Team Needs: Hands, Intelligence?
Effects:

Better control of shot distribution (making sure that the guys you want to shoot most, shoot most)
Fewer shots in the game (can help to overcome a talent defecit, particularly in rebounding)
Fewer handling related turnovers (travels, over-and-back etc)
More passing related turnovers (throws the ball away, intercepted upcourt passes etc)
Tends to have less overall turnovers
Decreases your 3FG%?

Team Needs: None
Effects: This is the baseline for comparison

Team Needs: Shooting, Rebounding, Hands
Effects:

Favours deep teams who give their bench more minutes
- Players from both sides should fatigue faster
Increases the number of shots in the game
- More opportunities for a superior shooting team to win the game by their FG%
- More opportunities for a superior rebounding team to generate more possession through rebounding margin
Tends to give guards more shots
- You can of course correct this with individual shot settings
More handling related turnovers
Fewer passing related turnovers (due to less passes)
Tends to have more overall turnovers

It should be noted that individual shooting settings greatly contribute to the actual tempo your team plays. The fastest game plan would be to run a "Upbeat" tempo with every player given a 9 for their shot setting. Similarly the slowest game-plan would be to run a "Slow" tempo with every player given a 1 for their shot settings.
Running upbeat just because you have a small lineup is a bad idea. It does not seem to generate more fastbreak points as you might expect and generally just results in a larger rebound margin against you. (If you're short, and deep, with good handling and shooting, and can stay close on the boards, then by all means try upbeat)

If either your shot distribution is not as you'd expect, or your FG% is lower than expected have a read through your pbp's. You may find that your team is passing the ball around too long and then throwing up low percentage shots to beat the shot-clock. You can fix this by either increasing the team tempo setting, or by increasing individual shot settings across the team.