1. Particle tunnels because it ALREADY IS outside the barrier. You just sometimes find it outside, sometimes inside according to its wave function. So, this is INCORRECT example. No violations of 1st law seen.

2. delta p/delta t operator is exactly the analog of force in quantum mechanics, F = delta p/delta t. So, indeed second Newton law is still valid.

3. Every action in QM has exactly opposite reaction. It can't be othervise, because it follows from symmetry of space (x is the same as -x). As a consequence, momentum conserves. I never heard that momentum does not conserve in QM.

Warm regards.