Let me clear this up, as I see OP doesnt have the first clue about how exactly these custom loadouts will work.
Primary weapons, will be a choice out of I think 3 weapons: The DMR, the BR, and lastly the AR. As you are aware of, some people prefer one weapon to the other, and like fighting at different ranges. For example: for a player that prefers to fight at long distances, they would choose the most viable option for that range: the
DMR. For a player that prefers to fight at mid
range, without getting to far or up close and
personal: The BR is their man. Lastly, for a
player that is a bit more daring and reckless,
and likes fighting in close quarters, they will
certainly choose the AR. This way, custom
loadouts will actually benefit each player to their
comfortability.
Secondary weapons: Now this, I am not entirely sure of. But of this I am nearly positive: they will not allow any explosive ordnance. Power weapons like shotgun, sniper, and the sword, and so on, I believe will not be accepted as well. I assume there will possibly sidearms, maybe some plasma weapons like the plasma rifle maybe. It all depends on what they allow, and ultimately, what suits the player best.
I hope this helped clear up your misconception on this particular topic. I do hope you reconsider your decision of not buying the game, just because of this aspect.