To be fair, you shooting lots of guns is wasteful because you're going to knock someone over, and all that extra ordinance goes to waste on a temporarily invincible target. So I don't see why you want to alpha strike someone.
Thats kind of the reason, a faster damage burst and Stability break to deny how easy it is to rush into people with melee. This will force a melee player to be more cautious of just charging in against someone who has a Gun while at the same time being risky for the person with the gun as they could run out of Boost doing this. In a game like this it is inevitable your opponent is going to enter an invincible state its why they are put into it that matters.
You seem to be vouching for specifically ranged focus combat. This, I disagree with.
To address your solution to the presented problem, firing all the guns isn't really going to help you here. If I side strafe around you, I'm not going to get shot. You firing more bullets at me that still miss is not going to solve your particular problem.
As to why I disagree with your purpose, the last thing we need is for this to turn into a gun game more than a melee game. It feels like it was designed so you can quickly close with people to hit with swords. Making it harder to do that would promote people playing keep away and time out to win.
Guns as a primary loadout require much more investment, which is fine. They're there to help melee, which is probably why you can have 4 ranged weapons as opposed to 2 melee. By design, they're less powerful because you can equip so many.
Given that multiplayer is coming along, the last thing I want to fight when I go online looking for a quick game is someone shooting me like, once, and then running away and exhausting the timer.