Re: One question about keyboard+mouse controls
I believe they said they're unifying the controls across all three games, but I don't know what that means with regards to keybindings.
In ME2 and ME3 squad commands were set to Q and E (on a WASD keyboard), and they said ME1 will adopt this system. On top of that, they also said that melee attack will be be a separate key in ME1 just like it was in ME2 and ME3. If 'F' remains the 'first aid' key, and 'R' the grenade key, I can't imagine there being a separate 'use' key. I also fear that everything will be mapped to the space bar, but that's all speculation.
If it were up to me, first aid in ME1 would be merged with 'unity', so it would end up on the quick bar. In that case, F could be the 'use' key, shift the 'sprint' key, and space the 'pause' key across all three games.
Edit: I just realized I forgot about the melee key four sentences after I brought it up. If F is melee, then that's not a good sign for a 'use' key.