Anyway I can use the crosshair in 3D? I had to go back to 2D because of it, I rather play in 3D but the lack of crosshair just ruins it for me

The laser sight was added to 3D to maintain the illusion of depth. A static crosshair would ruin the illusion. Unfortunately, there isn't a way to change this.

A crosshair never ruined the illusion in other 3D games I’ve played :\ the laser is just stupid and doesn’t even work well.

For me crosshairs are a bother even in 2d mode :/
I play Doom3 without a crosshair
You can do this in 2 ways that I know of. You can edit the crosshair texture to being nothing, or you can use Sikkmod to remove it.

Of course for the BFG edition I wouldn't even have to do these. Cool, me likes.