Hi Lluís,
1. The fuel quatity: By reading the manuals I have learned to work with the fuel transfer (or at least I think so). As far as I understand, there is a single gauge to display the fuel quantity of the tank in use, but I only have readings of quantities when the tank used is the Forward Fuselage one (lower cell). This means that I do not know how much fuel remains in the active tank when this is not the "lower cell".
the fuel quantity indicator works as follows: As long as there is some fuel left in the drop tanks, the needle shows that amount. When drop tanks become empty or are being dropped, the needle automatically indicates the remaining fuel in the internal tanks (total fuel of all tanks). Little problem here is, that if you forget to turn on the fuel transfer pump in time, you may run out of fuel although the fuel quantity needle still indicates a lot fuel (that from the aft fuse tank, but it is not usable without transfer pump).
2. The VOR/DME: The radio system is capable of tuning VOR stations (not yet sure if also ILS). I tune any station without problems but I have no information on radial to/from the tuned station and neither on DME.
Of course, you can fly ILS approaches with the Sabre, too. Just do a left-click into the radio compass card and it transforms into a VOR/TACAN course indicator with glide slope needle. For a DME, click into the mach number indicator. If needed, there also is a two-needle RMI hided behind the turn and bank coordinator, just click into that gauge to make it visible.
Both, the DME and the course indicator also can show GPS data (bearing and distance to next active waypoint) if the NAV selector switch is in position
AUX.
I'll send you a PM, too.
Cheers,
Hansi