Light Saber for ME:A

We saw a very quick glimpse of a hammer in the VGA trailer. The animation even looked the same from ME3MP. 

I'm curious about one thing: Are the settings in the shields changeable?
Can people in ME-universe change how fast an object have to move to activate the shield?
In that case it would theoretically be possible to make it able to stop melee weapons that come in a high velocity, which it would have to for it to go through armor.

Armor that can stop or deflect projectiles fired by mass accelerator weapons should be able to do the same with Kai Leng style ninja swords. The latter is going to have a lot less kinetic energy, even if it is wielded by a cyborg. A person in body armor should be completely impervious to damage from someone who brings a sword to a gunfight.

The other issue with swords or other melee weapons like war hammers, is that they are only useful at close range and monopolize the use of your hands. A person wielding a sword or hammer, even if it could kill the person beneath the armor, has to opt to trade a weapon that can kill at both long and short range (firearms) for one that is only useful when you're eyeball-to-eyeball with an enemy. It's a poor trade.

There's no amount of writing that can ever make swords and war hammers plausible as anything other than obsolete weapons. Unfortunately the devs are prioritizing Rule of Cool over verisimilitude on this one.

Lore wise, armour doesn't protect you from bullets in Mass Effect, the shields do. Well technically the the shielding is coming from the armour, but that's not the point.

Armour would help protect you from shrapnel, ricochets, environmental stuff like fire and gas and so forth. As well as dispensing medi-gel to any injuries and emitting the shield, but it doesn't stop bullets.

Tactical Cloak, Biotic Charge, Biotic Aegis....

Superior mass effect shields.... Sneaking up on them... or waiting just around a corner as they come rushing. Being shield penetrating it could be quite deadly in close quarters, one of those monomolecular blades are sure to be nasty once they cut in. Unless the wearer got similar materials in the armour.. which I imagine would be a challenge to accomplish without it being dangerous to the wearer, and very expensive.

Offence and fecence usualy goes hand in hand but it's usualy a lot easier to get proper offensive capabilities than a defence that's up to the task. Usualy the best defence is a good offence because then you stand a better chance of stopping your enemy before they hurt you. Failing that you will be left taking a beating til your defences fail.
That blade combined with Biotic charge could be a nightmarish weapon, If they survive the charge then you cut them in two, then you charge again. Unless the enemy instant kills you with a similar blade once you arrive and ignores the staggering effect completely.

In multiplayer that works best for Bronze and silver, after that the enemies start instant kill you once you jump at them, nm that you drain your shields at the same time as their damage has reached levles where one hit will drain your shields or kill you if down.

While it stuns nearby enemies, it also drains your barrier, leaving you at mercy of anyone not right next to you. Using sword/hammer leaves your shields intact.

A real life battlefield is not a game a video game. Sometimes you have to capture a spot, or get from A to B as quickly as possible. That are many instances one might find himself having to rush the opponent, and not just in war, it is probably a common scenario in police operations.

Also, I doubt many people are arguing to melee weapons INSTEAD of traditional guns. But as a complement. 

A melee weapon like a sword would replace firearms however, because you can't realistically dual-wield swords and firearms. Using a sword would monopolize use of hands that would be better spent wielding a firearm. Why would anyone realistically trade a firearm for a sword, when the firearm is just as deadly, if not more so, and has much greater range?

The only justification for weapons like swords being in the game is Rule of Cool. It's just a question of whether or not swords are cool enough to abandon verisimilitude for. I'm in the no camp, but that's a subjective opinion. 

There is nothing in the games that indicate that shields are the main form of protection from incoming rounds. They are the initial layer of defense, but that doesn't necessarily mean it is more important than the other two layers. 

The Terminus Systems in fact do not even use shields. Although it isn't always reflected in gameplay it was mentioned that shields are uncommon in the Terminus, so body armor alone is capable of deflecting incoming rounds. Shields just provide an extra layer of protection.

A sword should not be able to bypass armor that is capable of deflecting mass accelerator rounds that impact with much more kinetic force. The swords used by Kai Leng and the Phantoms (sounds like a band!) are a contender for the Things That Don't Make Sense thread.