Isn't that the scene where she literally turns into a bawling toddler in a night gown? I know what they were going for, but it failed and it made Samus look like a weakling. She killed this thing like half a dozen times at this point.
Also, about her not being subservient, why would she let herself get burned in the thermal zone if she has the Varia suit and can shield herself whenever she wants? Unless she has some weird kink thing going on with Adam.
PTSD doesn't work that way. She makes it very clear at the start of the game that she thinks Ridley is gone forever. She finds out he's alive again despite all odds and has a relapse remembering the trauma, which happened when she was 3 years old. It lasts 1 minute. She then kicks his ass.
The authorization system was made mostly an excuse for upgrade progression and much less thought was put into it than the fan fiction about Samus running through the lava area as part of a BDSM role play with Adam. The reason stated in the game is that Samus' upgrades could pose a danger to the other people on the mission and Adam wants to analyze each one to guarantee safety before authorizing each one. Why the Varia feature is one of those things is never explained. Maybe the Varia feature could emit lethal radiation or something. Since the reasoning for that part is made up, why not make up something like "Samus enjoys a challenge and wanted to do it without the Varia suit instead of asking Adam to authorize it." In other games like Super she inexplicably just leaves the Varia suit and the rest of her upgrades at home and makes things harder for herself than they needed to be, so why not?