A few questions "ie why are the flankers engines bare metal?"

so yeah here are some of mine:

why do all flankers have unpainted/bare metal engines?

why not make your external fuel tanks LGFT (Laser guided fuel tanks?) or slap on a tail kit on a fuel tank to make it gps guided? – Sure a fuel tank wont get through a bunker, but it might be good enough to destroy a comms tower?bomber?another aircraft etc?

Simplification: LGB basically wants to hit a laser spot on the ground, so around bases why not have stronger laser emitters that guide the munitions towards themselves and saves the intended target that is being targeted by the pilot?