I've got myself into a bit of confusion over encounters and what other players can do to help you when it's your turn and you're facing a bane.
2. If you are at a location with another player, can you combine both your melee rolls into one big total, or do you have to attack singly and in sequence?
Unless the bane has more than one check required (i.e., Combat 8 THEN Combat 11), only the active player is playing the primary cards (i.e., using cards that say "your check"). If there is two checks required then the active player can do one and the other player at the same location may attempt the other (note: if one character fails his/her check, the other player does not get to re-attempt it)
Others may play cards/powers to assist -
only cards/powers that say "at your location" if they are present at the same location
only one card of each type