I like things how they were in beta.
I hope stuff is new but not like your suggestions.
Edit: Due to this idea being disliked by virtually every person (for various reasons) I'm no longer responding to most of the posts. I had the intention of actually discussing things with people, but things didn't really end up that way most of the time. I'm pretty sure most thought I was suggesting making some guns class-only, although I never said that anywhere. I was saying that certain classes should be better with certain guns but really my suggestion wasn't that specific at all. Also, I'm pretty sure it's much too long. Oh well :D
THERE IS A TL:DR AT THE BOTTOM!
I don't know if there has been a post like this before. I'm a strange one I guess, but I'm a fan of class specific bonuses to guns. Don't get me wrong here, I like for every class to be able to use every gun, but I feel like by making them usable on the same level by every class pretty much ensures that everyone is just going to use Auto Rifles, probably Fusion Rifles, and LMGs. They would specifically avoid Hand Cannons and Pulse Rifles. Weirdly enough, my class separation goes all the way down to the starting species. As clearly as the weapons have a class specific lean for me, the races do too. For me, Awoken seem like Warlocks (duh), Humans seem like Hunters (being more fragile and faster than robot-like entities probably), leaving Exo's as Titans (Robot-things probably being more submissive and soldier-like, which Titans feel like to me). I'm not going to go as far as to say certain races should be certain classes, but I wouldn't mind if races had different bonuses that lightly "pushed" towards a class. Oh, and I write too much due to not wanting to leave things out and reading quite quickly and I overuse parentheses. Just in case it becomes unclear, what I'm suggesting is pretty much the TLDR, and the rest is mostly explanation or raving.TLDR at the end for those of you who just aren't fans of reading "large" things, or don't find my writing worth it. The TLDR does take most of the life and explanation out of it though.
Everything needs to be rebalanced, regardless of whether or not these changes take effect. Now, the first issue is that the way the guns are placed on the primary/special/heavy spectrum is 4-3-2. That could be resolved a couple ways. The first way I can see is pretty clean, simply making the "Hand Cannon" a special weapon, and making the Sniper Rifle a heavy. Either that, or replacing the Pulse Rifles with the Hand Cannons in this, which sounds weird. This, of course, would need to be changed for balance, probably by buffing up the Hand Cannons considerably, as well as the Sniper Rifles. Or, the Hand Cannons could remain a primary and become a non-class specific weapon, and then some kind of new heavy or special weapon would need to be introduced. I don't like the second method for reasons I'll explain later. These buffs could be different than traditional stat boosts, like for instance the Hand Cannons could have an extra fast switch to time and/or reload speed, or mobility speed bonuses, or killing an enemy with a Sniper Rifle gives a greater drop chance for heavy ammo. I also think the Hand Cannon should be re-specialized for close range, if it already isn't ( I used it for 10 minutes, and realized how utterly horrible they were, like the Pulse Rifles). There are many possibilities, those were merely fleeting suggestions.
In terms of the class breakdown for weapons, for me it would optimally be the Auto Rifles, Shotguns, and LMGs for the Titans- them being the most short range and the bulkiest, they get weapons with more raw power and with short-medium range. The Warlock was slightly harder because I feel like they are the ones that rely the least on guns (lore-wise, at least), and have less specialties relating them, and the other guns fit other classes better. For them, I'm thinking the Pulse Rifles because they are a combination of both other primary weapons, they seem to like burst weapons, and to be honest, the name - not burst but pulse, feels sort of techno-magic-like. The special would be Fusion Rifles, of course, and the RPG would be their heavy, because it doesn't fit the Hunter and ranged splash damage is the Warlock's thing. The other possible primary would be the Hand Cannons, if the Pulse Rifles got moved down. This due to the whole less reliance thing, carrying a smaller weapon accentuates that. And then the Hunter, my favorite, I'm thinking Scout Rifles, Hand Cannons, and Sniper Rifles, for clear reasons like range, precision, and directed power. If, for some weird reason, the Pulse Rifles got moved to specials this would be theirs, all though I don't like it much. If the second method from the top was chosen, a new special or heavy would need to be created, if it was a new special than an old one would have to be turned into a heavy (or, you could add more weapon types and just make them unspecific, although making more would be difficult). Perhaps the damage types could also have class bonuses or be mostly used by one class, like arc for Titan (their electro fist comes to mind first, and the fact I see them as Exo's for some reason), solar for Hunters (their golden gun disintegrates things, and fire seems more human than anything else), and void for Warlocks, (seeing as it doesn't fit anything other than them and their first subclass is called voidwalker, but it doesn't help that their second is called sunsinger regardless of the fact that it's mostly team based). Perhaps the Warlocks could have all three but be special by having domain over void, and the Humans could have domain over solar, and Titans over arc. I also wish certain classes pushed more towards certain things, like melee for Hunters, grenades (that could be disguised as magic) for Warlocks, and gunplay for Titans. Perhaps they already do, I don't remember everything from the beta, but I feel as if they could push more regardless.
In terms of how these bonuses are applied, it could be in a variety of ways. They could be within the gun's basic stats, a certain bonus on a gun (I.E. a Scout Rifle gives bonuses to Hunters when the 'attachment' is unlocked and purchased, or maybe attachments can only be unlocked on a type of gun by a certain class), or in clothing. Maybe there could be a few exceptions, as in weapons that can be used as well on all three classes, or weapons that can be used better by the wrong kind of class.
This is a reasonably viable solution to the fact that some have complained about a lack of difference between classes. I understand that this is only a suggestion, most likely not going to ever be implemented, many will disagree, and it's almost certainly too late to implement. I'm okay with all that, I just like suggesting things.
TL:DR: Hunters should be good with Scout Rifle, Hand Cannon - which should be made a special, and Sniper Rifle - which should be made a heavy. Warlocks should be good with Pulse Rifle, Fusion Rifle, and Rocket Launcher. Titans should be good with Auto Rifle, Shotgun, and LMG. Explanation above. Of course things would need to be balanced, and some guns would probably be exceptions, although this isn't an absolute suggestion, and the guns for each class could vary. The method of making certain classes better with certain guns could be applied numerous ways, some of which are suggested above. The bonuses don't even need to be that large, just enough for someone who doesn't like their classes' gun type to stop and think, "Hmm, maybe I should try it and practice using it". Besides, haven't you got the feeling that many guns were intended for a certain class? This adds roles in combat, adds some logic in that a Hunter would want to use a Sniper and a Warlock would want to use a Fusion Rifle (etc.), and makes each class more special and real, so it doesn't feel like your training the same character up to level 20 three times.
EDIT: The feel I'm getting from most is that they want it to be closer to a traditional FPS which is... weird.