I agree and disagree with option 3. The characters that would normally start with Assault Rifles should be allowed to choose any Assault Rifle, except the Lancer GL, i firmly believe that should be a JD weaopn only, Command staff and all that. Characters that use Snipers should be allowed to use any and all Sniper type weapons and Explosive character users be able to choose any and all explosive type weapons. Engineers should be given the worst type of weapons in the game, as they do not need them, their job is to build and repair, and they should stick to that.
And, it is not a weapon as such, but i do believe it is time for the Turret to return, it is much needed. At the moment the game lacks certain things. I do not know about anyone else, but i have found that the first half of the game for the Engineer is building Barriers and Weapons Lockers, Sentries are build lastly, and it is almost like they are not needed in the game anymore, or more to the point, not enough Energy to build as we once did in Gears of War 4 Horde. Using Energy for Perks is and will always be a mistake made by The Coalition, these skills should and need to be earned by experience.
And, whilst i did mention that Sentries seem to be less needed, it does not mean that the Turret is less needed too. It is not just the Engineer that uses the Turret. In Gears of War 4 Horde i would often build a minimum of 2 Turrets, and upgrade them to level 3, rarely to level 4, depending upon the team and Energy. In Gears 5, with the Energy situation as it is, i doubt i would ever get a level 4 Turret (exaggeration).
So, yeah, option 3, i agree and disagree with. Yes, open market on the weapons, but only certain weapon types to certain Classes/Roles/Heroes.