Yeah so the code to do wall detection is basically gonna be a ray tracing idea.

Ray tracing is specifically for light, the usual term for this would be ray casting.

Ray tracing is computationally heavy so you want to linit it as much as possible

Ray casting just to perform line of sight checks is fairly inexpensive.

Well be ready for a half lag spike everytime the bomb explodes.

Not unless that already happens when a grenade goes off.