Imagine thousands of people not succeeding in crashing a megacorp on purpose, and then one rich guy crashing it just by being stupid

Depends on your use case, but any up-to-date distro is secure. Security issues mainly comes from the user’s actions.

The best move depends on the depth of the calculation With a depth of 1, the best move might be to just take a free piece, and with a depth of 20 it might be moving a pawn for positional advantage