What I'd like from ME4 multiplayer:
1) the ability to map on our own, without having to jump through the hoops we have for ME3
2) No longer seeing maxed items showing up from the mystery bags.
Have the rng setup a few backup items, so if the rng roll says "here you should receive item x" another line of code verifies if you have item x maxed. If no, you receive the item and it shows on the popup of loot. If item_max=yes, it drops to the second item on the list, and repeats the check.
Note: this check should only apply to items that can be upgraded and not consumables.
3) Ability to vendor back, un-used/un-desired items for a small profit back.
Explosive ammo I'm looking at you here. Not talking anything major, but even getting say 5 credits back per rank 1, 10 per rank 2, and 15 credits for rank 3, over the short term it doesn't help, but in the long haul it does.
4) agreed with others, a pause feature would be great, for both pub and private games. Depending on how it may be implemented, a way to override the pause might be desirable. And probably a maximum pauses used per game (public) to prevent both abuse, and/or griefing