Were not all the companions codepedent? Wasn't one of the themes of Torment that the nameless one draws people to him and uses them?
An in-game justification doesn't make it any less problematic.
Sorry, but what 'justification' do you have in mind? It seemed to me that P:T took inspiration from eastern philosophy, especially hinduism and buddhism. Long story short - it(Buddihsm) implies that everyone of us have to walk through each of certain paths - path of adolescent, warrior, father and old thinker. Each step make us closer in recognition of our true selfs - ancient Greeks call it daimonion, on the east they call it atman(it's something like unchangeable part of soul, which allow us to transcend into world of ideas).
This unchangeable part of a soul is our target, something we must experience to know our true essence. To do so, we need to improve our karma in a chain of incarnations( cause it's damn hard to get rid of karma deposit in just one life spawn). Improving karma is only possible in interpersonal communication. This karma thing is our torment - something that we were supposed to do, but we didn't, like missing a warrior or old thinker path in our lifetime(Nameless One broke this chain by getting rid of his mortality, burying his chance for 'redemption', which made him, as hiver said, a load stone of Torment). Karma is charged also by being a dick to other souls. If we did something wrong, we need to fix it in our next incarnation.
Buddhism implies the whole universe of parallel worlds, so in our next life we land in one that's suitable for our karma. The one inhabited also by souls we hurt and those with similar karma. At the start of 'the game' you don't remember shit from your last life, you're loosing your identity, all you got is you karma and undiscovered atman. And those tormented souls, which may be helpful in improving your karma.
That's how I see interaction between party members in P:T, including those 'romance' thing with Anna and FFG. They are all chained by their "karma" and each one needs another to find his/her atman. Where the hell is there space for flirting?
TLTR version;
Torment cannot into relationships of the flesh cause it would be inconsistent with it's narrative
