The kind of material I’m looking for is while they were were romanized celts how much of each were they?

From the period I read, Roman slavishness was still in its infancy. That covered the direct transition from Claudius to Nero. I.e., "Romanizing" was pretty much a slap in the face for most tribes, at that point.

She was a noble woman so would she be doing a Roman hair style or would that have been dropped the moment she decided to go to war?

The GN's were poor upon such details, and again, the first two were pretty-much focused on setting up the whole situation, where she hadn't gone to war yet. But they did make an important point that her husband was humiliated so very badly that he retreated for a long time in utter shame (he literally got publicly bathed in shit by the Romans), directly leading Boudicca to take up the tenuous Celtic, regional reigns, in his absence.

From my read of history, that's actually happened many times over the years, here & there, so it does seem quite plausible.

Most of the other Q's I'd think are worth asking of PugJesus or r/AskHistorians, or similar expert. Maybe even an LLM. The books skimp on such details, sadly.