Nope. You just need to abjure separating the universe into system and observer. The Schrödinger equation gives a precise, non-probabilitistic equation for the evolution of the wavefunction of the universe.
And even if you have supreme confidence that thermal effects prevent any macroscopic consequences of quantum mechanical events (except maybe the disturbance in the air caused by physicists whooping it up when a 'quantum eraser' experiment gives a bizarre counter-intuitive result), what possible operational meaning can your 'determinism' have when so many of the models we have for classical dyanamical systems (weather and climate for instance) exhibit chaotic dynamics so that even were there an exact correspondence between the physical system and the Platonic ideal of the mathematical model, epistemologically there is no determinism anyway, since one can't know the initial conditions precisely enough to make predictions?
Talk your way out of i hbar d(psi)/dt= H psi.
See a random operator in there?
I'm not talking about epistomological determinism. I'm talking about physical determinism. Show me how something can 'guide' the system that isn't part of the Hamiltonian.
You, in turn, talk your way out of the fact the EPR experiment comes out the way it does.
There is certainly no science in the Popperian sense absent observers observing systems, so you are still left with explaining the nondeterminic behaviors observed in quantum mechanical measurement. Unless, of course, you have a non-Popperian view of science, in which case, I wonder on what basis you so hotly insist on science as a superior form of knowlege to religious experience.