Let me explain...
As a tactical and Heavy weapons player will be focused on the ranged combat. Eventually they will face someone who is armed for melee combat. So why not have the tactical and heavy weapons player use their ranged weapon as a shield and melee weapon? I imagine it won't do as much damage as say a combat knife, but still it would provide blocking and a push back too protect the player.

A kill counter on the hud.
How about making a kill counter indicator for the HUD? This way players can keep a track of their kills visually, instead of having too check a window in mid combat. It's similar to the Death Clock implant on the Khornates and Black Legion

Allow the player too see through their in game character.
I understand the game is going to be in third person. That can be a problem in events where a wall or corner blocks/ obstructs the camera. So why not allow the in game character to go transparent in the event of a melee combat or other camera collision event?
I've seen many games suffer from this third person problem without proper visuals of the combat. Games like Space Marine & Gears of War come to mind. I'm sure there are others, but I cannot name them at this time.

These questions should be more for the Game Designers to answer, but I'll try answering them for you.
We still need to make a final decision of these things, so please take my answers lightly

1) Range/Heavy weapons should be usable to block incoming melee attacks (kicks and weapon butt attacks should also be used to attack/counter-attack if you don't have access to your Combat Knife).

2) Kill Counter should be there only if it is useful (i.e. some Rage attacks could be possible only when a certain amount of kills is reached). But as a simple stat, it will probably and sadly be nested in a Stats Screen (I want to leave as much space for the important HUD elements as possible).

3) About Transparent Character/1st person views in specific occasions... I sadly don't know the answer to that. I think we gonna try to do as much as possible with camera angle switch when needed, etc. and I think that your character will go transparent when needed (which could be only in certain tight environments, etc.).