What do you think of a couple living together outside marriage?

I honestly don't think anyone could answer any of those questions for anyone other than themselves except in a spectacularly generic and utterly useless way. It depends on the couple. It depends on the relationship. It depends on the marriage. And the couple.

Which is true of any marriage regardless of whether you live together or not.

My love interest believes that as long as two people are self-sufficient and are going their own way under their own power independently then their relationship is moral. Any compromise on morals(that pertaining to the demand that one live for the other or that the other live for them) is unwise and results in hardship, suffering and great psycho-epistemological trouble for both of them. For that matter, the stage of the knowledge of self that requires maturity and responsibility is a determining factor (whether they are able to take the relationship seriously) It is our belief that the possibility for one another to evolve over the course of a relationship is a value in itself. We feel this way on the premise that sex is good and beneficial to the furtherance of the same values upon which the relationship is based (proper context and an ideal circumstance from which to grow and develop). Furthermore, the two of us are united by reason, mind and reality and that presupposes that no license, ceremony nor interloper that bestows the covenant of nobility on our affections or secures our de facto admiration for one another in the holy rite of wedlock is desired.