So in your design, you'd have to figure out a way to prevent self-halting under all possible input conditions, under all possible self-modifications of the machine.
Self-modifications are being performed by the machine itself. Thus we (and/or machine) don't need to prove that all modifications aren't "suicidal". Machine can be programmed to perform only provably (in reasonable time) non-suicidal self-modifications. Rice's theorem doesn't apply in this case.
Edit: However this leaves meta-level unpatched. Machine can self-modify into non-suicidal machine that doesn't care about preserving non-suicidability over modifications. This can be patched by constraining allowed self-modifications to a class of modifications that leads to machines with provably equivalent behavior (with a possible side effect of inability to self-repair).
The kind of constraint you propose would be very useful. We would have to first prove that there is a kind of topology in under general computation (because the machine can change its own language, so the solution can't be language specific) that only allows non-suicidal trajectories under all possible inputs and self-modifications. (or perhaps at least with low probability, but this is not likely to be computable). I have looked, but not found such a thing in existing theory. There is work on topology of computation, but it's something different from this...
In the novel Life Artificial I use the following assumptions regarding the creation and employment of AI personalities.
(Note: PDA := AI, Sticky := human)
The second fitness gradient is based on economics and social considerations: can an AI actually earn a living? Otherwise it gets turned off.
As a result of following this line of thinking, it seems obvious that after the initial novelty wears off, AIs will be terribly mistreated (anthropomorphizing, yeah).
It would be very forward-thinking to begin to engineer barriers to such mistreatment, like a PETA for AIs. It is interesting that such an organization already exists, at least on the Internet: ASPCR