RNA editing and Convergence, powerful evidence for design

Convergence of any kind is not contrary to evolution,
nor does it make any comment on common descent.Convergence is about the existence of similar properties
that come about via differing mechanisms.Common descent is about the same property by the same mechanism
being exhibited in different types of organism.Both are explainable within the evolutionary paradigm.

Show me that DNA/RNA chemical systems a genuine codes first.If they are not then the whole line fo argument fails.It's just chemistry -- albeit highly complex in terms or
interactions.

I've not said that at all.What I have said is that they are separate/not-connected
and thus can say nothing about each other.Common descent cannot be an antithesis of convergence any more
than wave motion is the antithesis of particle motion.They are used to explain different observations.Both are compatible with evolutionary theory.Likely both have happened (time and again) in the past.