I'm mostly referring to the Frag grenade. It seems to do poor damage output than say compared to an assault rifle with enough marksmanship to negate the -30% damage rule.Not mention imagine your face when you're at 25 range and the stupid thing misses against a horde and didn't explode as if it was a dud!
My recommendation is this, either beef up the minimal damage or increase the range. I don't mind if I have to pay an extra cash so as long as I know to weapon is actually effective as an emergency last resort (Well just not past $1000 a piece is okay).
In addition, I would really love it if the grenade could do some splash damage to nearby zombies, not as big as the target zombie being thrown at but something like 3-5 damage on zombies that have only a small difference in distance. Let's take an example.
Zed A(40 HP) is 45 dis
Zed B(15 HP) is 38 dis
Zed C(5 HP) is 52 dis
Zed D(20 HP) is 100 dis
All of them I'm attacking at once.
I throw a Frag grenade at Zed A, the damage results will be like this:
Zed A(0 HP-dead) is 45 dis
Zed B(10 HP-5) is 38 dis
Zed C(2 HP-3) is 52 dis
Zed D(20 HP) is 100 dis
Zed D is too far to be hit by a frag grenade considering his distance, while nearby zeds take the shrapnel splash. This item could be very useful in clearing out buildings quicker given in the enclosed space. However, it is also possible to get yourself hit if the range you throw at it is too close for comfort, like say within a range of 10 or less. You would get hit by the shrapnel too.
Next, the Heavy MGs, Frankly I find these weapons 'weak' that even their assault rifle counterparts are far superior, they weight more too and their ammo isn't the most common thing to find. So far only the PKM outshines them and by far I consider it a true heavy MG. I think all heavy MGs should have the bonuses of having better fire rates than the assault rifles (about 5-6 bursts should do it), with the draw back of having lesser range. You may add having them to have accuracy penalties as Heavys MGs are really hard to control (unless you have a tripod or something which could benefited by technical skill if it gets implemented.). In theory, more burst rates = more difficulty to steady.
In addition, guns that use rifle rounds and MG rounds should have a natural AP (Armor Pierce) bonus to them, as well as the revolvers of pistols instead of having separate bullet categories such as 9mm AP. Guns using 9mms generally have the advantage of having more bullets anyway.
And finally for melee users since I think they're the most underrated class that deserves attention, now more than ever since Zeds in building are cutting it seriously close by the numbers but I'll save that for another category, it's more character-based than item.