In an effort to help Tomas out, I'll try to answer your question, hopefully Tomas is cool with that
1. Sure, just get a spektrum remote RX to replace the included RX/gryo, bind it to your DX6, plug it into the uspirit and you are good to go.
2. The Talon 15 ESC can't monitor current and thus can't show mah consumed. Even if it did, spirit doesn't support spektrum telemetry. Even if that did, your DX6i isn't telemetry capable.
If you want telemetry from the spirit you will need jeti, frsky, or Graupner, or you can also have telemetry apart from the spirit, but you will need a telemetry capable radio system and a current sensor to go with it.
Hope that helps
schu