I think Lycus's speed is largely fine, considering his barrier. It lets him approach more safely than any other character, and makes him amazing at running down snipers It even regenerates while active, as long as you're running while it's on.
Also, the trick to Konstantin's gun is that you spin it up in advance by pressing the trigger before raising the weapon - he basically "preloads" his gun instead of reloading it. If you keep the spin/heat circle at the right spot, he starts shooting instantly, but pre-spinning raises stress, costing him stealth and preventing health recovery.