Balance suggestions

I’ve played a bit of ZM and have a few things that I feel should be changed.
For one, I feel the classes should be looked at again for balancing; some seem far more powerful than others (mainly, the merc.)
There are far more melees, at least in my experience, than firearms. This is nice and all, but I feel like the ratio between melee to firearm needs to be changed; less melees, more firearms. They’re too dangerous to be the main supply of weapon.
Lastly, I feel like the players damage, even when upgraded, is too little. Bullets feel like pellets and zombies feel like walls. It’s not a great feeling, and with picked up weapons this is still a problem.
Hope this is good feedback.