  We present and analyze a toolbox for the controlled manipulation of ultracold
polar molecules, consisting of detection of molecules, atom-molecule
entanglement, and engineering of dissipative dynamics. Our setup is based on
fast chemical reactions between molecules and atoms leading to a quantum
Zeno-based collisional blockade in the system. We demonstrate that the
experimental parameters for achieving high fidelities can be found using a
straightforward numerical optimization. We exemplify our approach for a system
comprised of NaK molecules and Na atoms and we discuss the consequences of
residual imperfections such as a finite strength of the quantum Zeno blockade.
