1) I think that there should be an option to choose between skirmish and elimination. Keep it in the 4v4 deathmatch just add the option to search for either of them or both. Right now if someone wants to play skirmish to complete an order or just play skirmish specifically they can't.
2) Invincibility while preforming an execution. A lot of the times when a fight is more than 1v1 and I try to execute someone so they won't be revived, I get slashed and it cancels the execution. Even when you are excucting someone you will still take damage that you can not avoid.