I have the same ADD issue with playing the sims as you do. The second generation rarely makes it to college before I get bored and delete the whole thing. I've vowed not to let myself do that with my shiny new MATY hood (Gen 2 is still all toddlers/babies/unborn except for the very first babies born, who have just aged up to child, so I don't know if I'm going to keep my vow or not).
For gender preference, I randomize with the ACR adjuster (I adjust the gay/bi percentages according to the gender balance of the 'hood). I plan let them pretty much choose partners for themselves. Like nekonoai, if a sim rolls the get engaged/get married to want, they get engaged/married, unless a couple gets pregnant, then it's a shotgun wedding for them.