What exactly would one have to add to the raws to remove the asexual and homosexual animals and dwarves? I really do appreciate the detail, but I just don't want to deal with the hassle of insuring a breeding pair.
Ensuring a guaranteed breeding pair, unless you want to guarantee insurance for your breeding pairs against damage. You can ensure your insurance for your own assurance, though.. Yeah, okay, I'm done. I had to.
Anyway, I have two possible solutions for you.
1.) What Insanity said.
I was actually going to quote your post from earlier. May I ask if it matters if the numbers are 0:0:100 as opposed to 0:0:1 that you had posted before?
And definitely use Edit>Replace or Find>Replace or whatever your text reader does. Still have not confirmed, but Notepad++ is said to be able to replace text on all open files at once.
2.) Add embark points.
When designing a world, by using advanced world creation you could simply add embark points to buy more animals for a much higher chance of getting a breeding pair. Since this is a new aspect to the game and needs some adjustment to work with, I consider it a house rule, especially since an expedition would more than likely make it a point to bring confirmed breeding pairs with them. At least 3-4 per gender of each animal is a pretty safe bet.