3 - Also, nice feature on the commander that you can spectate a group, are there any hotkeys to move inbetween groups, or trough the map, or inbtween units on that group?

Not right now, you'll have to go back through the command tablet and quit spectating before selecting a different group.

But when loaded the missions it seems it got stuck on the loading screen... I'll try to remake all from scratch, of change a phew things to see what could it be.

If you got stuck when initially joining the server (before choosing a unit to play with), make sure you all mods active on the server that are required to run the mission.