“Science has a very exact idea of the capabilities of evolution.”
Very exact? That’s a pretty bold claim. And what do we mean by capabilities? Are we referring to biological evolution on Earth or the algorithm of evolution in a broader sense?
How fast mutations spread doesn’t apply to the later. That is a tunable parameter in artificial evolution (which usually centers around not letting good mutations monopolize my population too quickly). The same can be said about what mutations occur (they don’t have to be random in an artificial environment) or how “breeding” works. These and other parameters are biological accidents on Earth, not part of the core algorithm.
If you want to say “it’s inefficient to mimic nature” then you should base that on the performance of humans who mimic nature not on nature itself, those are two different things. Evolutionary algorithms often work well in practice (including in situations where there is not an alternative that comes close), hence the more relevant evidence does not corroborate your hypothesis.
That is a very context dependent question.
Your safest bet is to just arrange meeting her in a context where sex is a possibility (for example: “hey, do you want to go for coffee then stop at your place afterwards sometime?”). The desire to have sex isn’t something you can forecast far in advance, it can quickly change just like the weather.
You can have sexual conversation and establish the general desire for her to have you as a sexual partner. Essentially like saying she likes a particular restaurant but doesn’t schedule going there days or even hours in advance, she’s just open to going there when and if she feels the desire.
As far as how to be good at sexual talk in general, unfortunately it takes careful practice. You just have to risk being akward or turning her off (within reasonable limits, don’t immediately test saying something too crazy). Trial and error within reasonable bounds.