Everyone is faced with this choice, even if you support them you are still functionally a prisoner with no real agency or resources. They just torture you less, how nice of them. 
The careful observation of the mc makes them not a non-factor by definition. They just judged the mc to be less valuable than sister and that is reflected in their treatment of the mc even now.
You can âpretendâ not to be a prisoner but that it is all it really is, pretend. Way I see it is that at that point some mcâs could have snapped far enough to play a âboy in the striped pajamaâsâ kind of headgame with themselves.
No, the mc never gets any leeway in Arcadia period. You just get to make a pretend âchoiceâ about some of the details of your servitude, but no servitude and actual leeway are never on the table to begin with.
The only part we seem to know for certain is that at some point old Arcadia stopped teaching their own youth their âsecretsâ due to their own paranoia. A likely terminally stupid decision, whatever else they may or may not have been.
Well Thalia claims to have ârelearnedâ a lot of old Arcadia by her own admission and her new Arcadia is certainly somewhat like the Naziâs with their magical bloodline obsession and genocidal imperial goals as the goal of Thaliaâs âresistanceâ seems to be the establishment of a genocidal Arcadian empire where the only people of some import will be Arcanists and she god-empress.
As @Gloomcat nicely sums up here Thalia and some of the other Arcadians certainly make a lot of points that might as well have come from the mouth of someone like Himmler.
Oh and assuming they have inherited the word from old Arcadia then the fact that the word for non- Arcadians, ercei also doubles as an insult can certainly be an important clue for insight into the mentality of old Arcadia as well.
After the last update there also isnât any ro my mc is interested in anymore. 
The only actual escape attempt currently in the game seems to be more about just getting away from Arcadia, not running to Param specifically. That wouldnât be my mcâs instinct by now anyway, heâs not anxious to be reunited with Leon either.
It is however doomed to fail, proving just exactly how utterly useless the latest parasite is. And unfortunately also how untrustworthy Eli can be. 

Oh and likely their own mother, but sheâs long dead and her legacy long since gone thanks to sister. Everybody else, including the parasites is just all about using the mc for their own purposes and donât give a shit beyond that.