Hi,
Yes you can turn off/on the the trails. No there is no bearing or distance given to a specific aircraft, we were trying to keep it as close to what ATC would see.
Regarding the preamp, a preamp and external antenna will always improve the reception. I didn't find any case of overloading however will ask the hardware guys to be certain on that and get back to you :)
Real time data cannot be shared, even if its within the same home network.
The flight level view may be added in the future if we have enough interest in it. As in the past in other applications we have found this feature was rarely used.
Hope that helps.