please help me balancing mines and making them more useful

[Suicide Junkie]

However, as special damage do *not* stack, will a special weapon try to take down a vulnerable component while the others cannot be destroyed?

Actually, that's a good question...

For regular damage, if the mine dosen't destroy a component, it was changed so that the damage stacks with the next warhead.
That fix may work for Only X damage types, at least for mines.