Certainly interesting input and ideas, I guess I'll go over them in the order you wrote them down:

1) Certainly something we feel like doing. Adding different statistics and advantages/disadvantages to the melee-weapons brings a whole lot of variation when it comes to the melee combat. You can already find something like this with the two melee-weapons in 1.13b where the bayonet has more range but a slower "rate of fire", while the club is a whole lot faster but has a smaller range. But yea, certainly something we feel like going deeper into.

2) Sounds like a nice idea, going to write it down and see if we end up doing it.

3) This is already solved in a pretty unique way. The game curently has a tiny bit of free-aim, which creates "float" on our weapons. (Basically makes it a whole lot harder to hit dead-center of the screen if you arent ironsighting) This in addition to a broader cone of fire should fix this issue, so good input.

4) We can solve this simply by not allowing the player to fire their weapon during ironsighting, who would actually do that in real life?

no comment :<

Currently we only use particle effects to simulate stuff like being hit by a bullet, but because of our pretty special way of handling ballistics it looks very different from what you might see in other source games and mods. Lets say you get an entrywound, but also an exitwound out your back, blood would come spewing out both ends. Our particle effects can be described as quite over the top and borderline hollywood-ish, but they look really really cool! We mainly want to keep it this way since it makes target confirmation with the ballistics-system a lot easier than it would have been without it. We might go further into the gore and gibbing system, I remember in a very old version of 2.0 we had some gibs. Maybe we'll bring something like that back.

Realistic movement to a certain degree is something we feel like doing for sure. We've thought about adding lean previously, but we're not sure at all if we end up doing it. On the topic of movement we have a very nice system in the game already which makes the camera-movement a whole lot more realistic when it comes to moving around like walking, running, going prone etc.

The MG deployment is actually already something we have tackled, but that too is also a work in progress. You can probably expect some videos on it later on.

Overall nice suggestions!