will the guns for the different players have different properties?
The way guns will work is like, at first, there are basic weapons which are like the weakest weapons in the game, so Dr. Walker tells you not to keep them since they're not worth it. So around Ansridge you'll just be able to pickup any type of weapon like pistols, shotguns, SMGs, etc.
However after Ansridge you'll find guns worth keeping, and you'll be able to equip them at any time. No matter which player you are, you'll be able to access the same weapons at all time
So the weapons will always be the same but there are some who can use weapons better than others, because their stats are specialized in using them.