Let's talk aliens.

[Treewyrm]

But, One would not be able to even be able to examine brain patterns of a Nomad?

Nope, I'm afraid. How a dead "brain" tissue would help? "Brain" is simply because of a lack of a better word, but whether it's a real brain or just receiver/transmitter... or something else. Who knows? Ain't much has been made out of that, other than more or less concluding they're collective beings, but the exact type yet unidentified. There is no bee queen of sorts, although some may suppose there might be one. Ultimately nobody seen one to prove or proven the lack of one to disprove that theory.

Bio-logical war-fare. Viruses, disease, evolving amoeba, Would Nomad be subject to any of that? Thou I think Nomad is a Infections disease itself. What if a Nomad was to merge with another Virus? Or Germ? Would it just infect the cells, or merge? Or would the cells have greater power over Nomad?

Nomads' own technology is largely biological in nature (hence their interest in human technology, which is quite distinctive from their own). I highly doubt they would be subject to viruses since it would assume they're not quite aware of bio-chemical processes happening inside of them, this however doesn't go well with the previous fact. Biological warfare would not be effective against beings who excel at that themselves. Plus Nomads are native to open space, their natural environments have no specific atmosphere composition either (unlike humans who either terraform planets or have to carry air supplies with them), making it difficult for airborne viruses to work.