Unless you get someone inside the team to tell you, the fuel loads aren't publicised. Each team will go through a set programme (weather and accident permitting) during each session. For the larger teams this is normally fine tuning setups and analysing tyre wear, the smaller teams will use this time for part testing as well to save on non race test time.
As for fuel loads the second session on Friday is normally where you see more laps being done in longer stints so obviously there has to be the fuel in the car to do this but the car has to be run at all weights to allow for a proper evaluation of the setup - there's no point in having a car which handles well full of fuel but is, for example, carrying too much wing to be competetive as the car lightens.
You'll also find teams running light flying laps at the end of the Friday session simply to improve their place on the timesheets, commonly this is done if the team have a big sponsor visiting or a big PR event that evening.
Red Bull are about where I'd expect them to be, Klien's up there because he's not subject to the tyre and engine restrictions of the race drivers, DC is about right and Luizzi's at the Nurburgring in an F1 car for the first time. Don't look at the gaps to Wurz for an indication of pace, Hiedfeld is the benchmark at the moment.