I assume you may be watching the somewhat gory but otherwise captivaativing series (due imho to the excellent characters and there development and the "plotting within Plotting"0.
Much of what you have seen is true.
I appears that Spartacus May have been a Thracian, but this is disputed by some authors, particulary Colleen McCulloch, who maintains he was a veteran of the Legions, and not an "auxiliary".
She sets forth in her books; which detail Republican Roman Times from the time starting while Gaius Marius (reputed to be "in trade", a black mark of the slate of a man with high polictical ambitions and the desire to accumulate as many clients and offerer of services as possible.
Roman Patricians held a multi colored role in Republican times. they could write wills and submit them for whateve form of Probate the Republic had, hear minor cases and plead and try all cases.
I additional to this status as a class borne aadvocate, he was also "pater familias" and held the literal lives of all of his household in his hands. He could order any member of the family to death. However, since so many partrician marriages were political in part, ordering the death of a son, daughter, or wife did not seem, to happen very often.
Due to the apparently availability of divorce, and /or fleeing to the shelter of one's own family, wives seemed unlikely tagets as a pratical matter.
Now to be in the Legions at the time of the Republic in the times of Spartacus on had to have land and a minimum monetary wotrth. The Semo Proffessional and later fully professional Legions were 150 to 200 years away, at the earliest, perhaps, subsequent to the necessary shrinking of the size of the armies after the end of the long civil wars which followed the muder of Gaius Julius Caesar.
A Partician, with or without previous military experience, could be named Consul and thus superior in rank to lesser patrician who served a "legatus" (legates) young patrician seeking military experience were brough into the Legion as tribunes, and Gaius Marius consered them a nuisance.
Having said that, if Spartacus was in the Legions at a time when citizenship had not spread to the provinces and the "provincials" he may have been a hardened soldier and a citizen of the Republic fallen on hard times, a the character "Varro" in the series had.
"auxiliaries" were recruited from "allied" state or the distant province ad hoc.
McCulloch made it it very clear that the man to assume the name of "spartacus" new the Gladius very well as he was disciplined several times at the "Luda" of the Lannista Batiatus when two losses of temper of his part caused some sparring partners to literally "lose their heads".
But, we can intuit to the fact that fight preset duels in the Ludas or the Arena was quite different from figting in the legionary ranks,
Please add comments. the next entry will try to detail the legions of the day and the major polictical players.
It is also important for us to take "as an artical of hitorical reality" thet, at this time, there were at least one slave for each four Romans in the Republic as it then stood in Italia.
Also, NO, repeat NO substantial state in ancient times could build a civilization without the institutional of slavery.
Ask yourself why and I will be back on this "Spartacine thread" soon.
"All Enlightenment Gratefully Accepted"