Slight hhv6 and parvovirus are " past infections" according to test.
Almost everyone has positive titres to some combination of EBV, HHV6, CMV, VZV, HSV because we've all been exposed to these pathogens and should be producing
some antibodies to them. A positive titre alone is nothing to be concerned about as a general rule. High titres years after the initial infection along with symptoms of the infection are another matter.
In your shoes, I'd go by Dr Dantini's interpretation of your pathogen test results. If he thinks your test results don't indicate a current infection then I wouldn't be concerned. If he feels they are infections that need treating, then I assume he will give you treatment.
In some cases, the specialist will treat the most important infection aggressively and hope that once the immune system is not so taxed with that one, it will be better able to handle the less serious infections. Only if those infections persist do they add in additional antiviral treatments. In other cases, the specialist will use multiple antivirals. That seems to happen most often when there are multiple high titres.
Valtrex is not a particularly good AV for HHV6, although it has some activity. It may be sufficient if you really only need to keep it suppressed.
Dr Dantini knows his stuff. If he's not ordering treatment for HHV6 and parvo, you probably don't need it... yet anyway. If you have questions about those pathogens, it would be worth asking Dr D what he's thinking about those results.
Who tests for cd4 and cd8? Dr Dantini just said likely Nk cells are likely and told me how to get them up naturally.
Some ME/CFS specialists do large immune function workups. NOVA University's Institute of Neuroimmune Medicine in Miami FL is one of them. Neither of those tests is absolutely necessary in order to get treatment for ME, they are indicators of immune function. Since there is no direct treatment for abnormal CD4 and CD8 cell numbers, you will have to decide what benefit you would get from having those tests. Dr D probably did not think you would get enough benefit to justify the cost. A majority of ME patients have low NK cell function which does seem to respond to certain treatments in some cases. It sounds like Dr D is on top of that.
I'd say you'll get better, more knowledgeable answers to your questions from Dr D than from a bunch of strangers on the internet.
The best we can tell you is our experience or what we'ver heard from our doctors, or read in research papers.