I think is fairly certain that ribavirin and interferon do not work against CVB4, as in the Invest in ME London 2009 conference, in the video at timecode 41:30, Dr Chia says:
Then at timecode 42:30, Dr Chia says:
In this part of the video, Dr Chia is talking about treating his son and some other ME/CFS patients with ribavirin and interferon, and how their CVB3 antibody titers dropped after treatment, but the CVB4 antibody titers were unchanged after treatment.
So I think this question is already answered; but you may want to see what Dr Chia recommends for treating CVB4.
I am not sure how important a question this is. Oxymatrine may have a lowish 19% bioavailability, but that presumably is taken into account when setting the oxymatrine doses. If the bioavailability were to be increase, then the dose would have to be lowered.
I can tell you the answer the LDN part of this question: Dr Chia says that LDN only works for a very small subset of ME/CFS patients, but he notes that the patients LDN works for get major benefits from it.
I know that Dr Chia finds Equilibrant to be slightly stronger in effect than pure oxymatrine, and some patients find Equilibrant too strong, so he switches to oxymatrine only.