Things you would change/add in MP.

I did forget about CAT 6 it would be cool indeed!

Also those are interesting changes to the enemies, i like the idea of them!
On that topic i would say for reapers like in ME2 armor added to the husks could be interesting (obv a tiny bit, and maybe when they get buffed by maurders, same with cannibals, to their bar instead of needing to shoot it off maybe)

Hmm also maybe engineers not only putting down turrets they could put down the shield generators (which obv can get destroyed easily and when enemy looses them tries to target them)
Oh and maurders having being able to set up those generators for barriers.

YES also promoting a character shouldn't be there seems like a waste of time..

1. Add collectors to platinum waves of other factions
2. Increase the probability of getting collectors in an unknown enemy setting.
3. More salarians and fewer volus shit (my ideal preference would be zero, but one for the sake of novelty would've been more than enough)

Edit: This is very important. Have the option of deselecting specific maps/enemies while searching U/U. 

TNS is a Collecturd h00r and hates Carebearus, so he's biased 

And it's not really U/U if you de-select certain options isn't it? It's called selecting things. 

A bunch of things, but most importantly I would add more Fat Turians

Store most game data server side, to easy to cheat/hack this game.

Well other people will de-select everything. So it doesn't make sense. 

And it's not U/U if you don't have the full spectrum. Unknown/Unknown means you DON'T know what you gonna get. De-selecting Cerberus and something like Condor, means you won't get Cerberus or Condor, that means you KNOW you won't get 'em and that's NOT U/U 

I must say this is pretty damn cool, you really have thought through it

Hmm Polonium rounds are available if the game is modded and does some % of your weapon damage to the target over some time. 

So maybe Polonium grenades, that could weaken Armour and take points off health (even when enemy has barriers/shields) for certain period of time.

That would have been great. I can't believe there were more Drell, Vorcha, Batarian and Volus characters than Salarian ones. Fuck you, Bioware!

- more options for lobbies search/setup. i'm with TheNightSlasher on this there has to be an option to exclude things like map/enemy. for isntance it'd be great now to have a filter exclude hazard maps to be able to recycle the map mastery quicker and without resorting to presets. with all the maps hiding under single hazard waves now it gets done early on and than it's just RNG trolling. also heard the PS3 folk has some issues there as well... but anyways, certainly more choices would do good there
- again more lobby rules, i'm talking filters now to exclude things like Reegar or certain characters... Theme lobbies/runs. enemies wave adjustments, so no need to mod outside of the game. the potential for abuse is high but that would be make it much more entertaining
- and sort of ties up with the above (can be a matter of the added filters as well) but the better matchmaking would be really nice especically around latency/geography... i do appreciate that we need to maintain a healthy population to ensure lobbies fill up and all but make this an option, or leave it for the player to decide
- better match statistics, plays of the game, meaningfull leaderboards, more challenges
- design with the regular events in mind, not an afterhtought as it was with ME3MP
- less bugs and better experience overall, not sure if this is moving data server side, optimized coding or what. look at Overwatch it manages to offer more fluent gameplay and while still subjected to the same network condidtions you rarely get to the level of frustration one can encounter in ME3MP, surely MEA can do better
- more factions, being able to play the enemy as well. i want to be able to play as a Cannibal or a swarmer already! Variety is the spice of life, ME3MP was a good start let's have more.
- and last not the least longer support lifecycle!

I have a feeling if they did add the option to select and deselect maps and factions it would not work anyway.
So it would end up being unknown unknown anyway.