Even if we aren't worried about FIGHTING the Romulans, we do still need plenty of information about them. The more we know, the easier it is to maintain positive relations, not just negative ones.
I suspect that IC, the Federation is almost entirely ignorant of even the most basic facts about Romulan culture, given what lengths the Romulans went to in order to make that happen prior to the events of the TOS era. There MAY have been some cultural sharing in the abortive detente that led to the creation of the failed Nimbus III colony, but probably not much.
I'd like to warn people before using that mining colony as an appeasement.
Remember, the Dawiar are an aggressive martial culture. We don't know how much of the current mess is a misunderstanding and how much fully intentional.
Trying to appease a warrior culture will be seen as a weakness and only embolden them.
Instead, use it as a reward for good behaviour. Tit for tat. If the Dawiar reciprocate our diplomatic endeavours, give them the carrot in form of the colony. Else, keep it back.
You are making assumptions about what "a warrior culture" actually means. There are a lot of different "warrior cultures."
In some "warrior cultures," an outsider who gives you something when they don't have to, or acknowledges your possession of something when they don't have to, is a weakling. But these cultures are relatively rare. And they tend to be savage and primitive, because if that influences their
internal dealings, then it results in them not being able to trust each other and cooperate among themselves. Societies that adhere to the notion of "what's mine is mine, what's yours is negotiable" on a day to day basis have trouble coordinating large projects that don't break down into internal squabbles.
In
other "warrior cultures," conceding something you ultimately don't need can be a gesture of magnanimous strength, or even a subtle way of proclaiming superiority: "I can beat you with one hand tied behind my back, and we both know it, so I can give you things as a signal of my respect for your moxie." They also provide an excuse NOT to fight, which even warriors often go out of their way to look for: "We can't fight that guy, he was our host at that big party! We owe him!"
And it's very easy for a "warrior culture" to resent "carrot and stick" treatment. "Carrot and stick" is how you train an animal, or a child. In relations between mutually respecting adults, while the carrot and stick are both
there, one has to be subtle about how they are used. Because independent-minded adults (and independent-minded nations) often have limits on how openly they admit they fear the stick, or covet the carrot. "Warrior cultures" where the desire for gain is seen as ambiguous, and where fear is openly despised, tend to have that problem with redoubled force. Because pride is a major factor in their decision-making process.