If I refused to use privative software at all, I couldn't even use a phone (even if the soft is free, the GSM firmware won't be).
Yes, you can. Try OsmocomBB (http://bb.osmocom.org/trac/). It's a free software GSM solution for several Motorola phones and the Neo Freerunner.
You do not touch my point. You seem to agree that a conscious entity arises due to information evolving over time. Let us keep this assumption.
For the sake of the argument let us further assume that everything you described is actually possible and that you can transform into a conscious entity experiencing infinite subjective time. Even then entropy flies in the face of your argument. The problem is that you cannot conserve information indefinitely - even if you try with all the resources in the world. Sure, you would have a conscious being experiencing time continuously. But after waiting sufficiently long that entity would have absolutely no information about the present day. It wouldn't share any information with you. This does not only include memories but also behavioral patterns, world views and so forth. That being could have evolved from any other being living today, you wouldn't be able to tell. Thus, that being won't be you given any sane definition of identity. You would be gone for sure.
Several of your other assumptions are very strong. Everything you describe is discrete: computation steps, finite state machines. The brain is not discrete and simulating it exactly using a finite state machine is impossible. You might argue that you can simulate it with arbitrary precision given enough resources and that might be sufficient depending on your notion of identity. It is my personal belief that this is impractical. (As a side note I am convinced that the notion of an evolving consciousness per se is all rubbish anyway; if you could generate an exact copy of yourself, which one would be 'you', the copy or the original? None, obviously. Consciousness is fixed to a point in time.)
In any case information degradation is a fundamental problem for immortality.