This is next suggestion which should decrease amount of alts if would be implemented.
Firstly, let's find answer for question "why there are is many alts?".
There can be many reasons but the most noticeable is that powerbuilds can't or don't want to craft ammo for their guns.
Main part of my idea is to make gun useable only for characters with enough high skills. That means, if you want to use sniper rifle, you will have to have these skills which you need to craft sniper rifle (so, not only small guns but also repair and science). Same for other weapons usage (I am thinking about same with medicaments but I think you will protest).
To avoid crafter alts Devs need to make schemes which you will need to craft f.e. sniper rifle. Schemes of weapons from third (or maybe second) profession level shouldn't be able to buy from NPC but can be only found in quests or on special encounters (that will avoid also that what is now, everyone have best weapon and win depends only from that who got better powerbuild). Then you will need not only skills, profession level but also scheme to craft the item.
I am just thinking now about that schemes should dissapear after use or not? If yes, then there won't be trade of schemes, if no, then there someday again everyone will has best weapon ingame and will be as I wrote above.
In sum, almost everyone who I said my suggestion said it will really avoid making powerbuilds but now I am afraid in this game most of players are powerbuild and they will cry shame I want to destroy their fun.
Say no to powerbuilds!