Without reading any of the other posts...
I'm thinking that height has nothing to do with it; rather, weight is the determining factor. Weight is proportional to levels of body fat and muscle, and therefore with the amount of water a person retains. The more water, the more alcohol it takes to achieve a certain percentage.
The thing is, if you take a group of equally built men or women, the weight will be directly proportional to height, and thus you will see a correlation between height and ability to handle alcohol. I think you can also say that, given a group of people with equal weight, height will have an
inverse relationship with blood alcohol levels, because shorter people will have more fat and/or muscle than taller people of the same weight.
I'm going to take a shot in the dark and say that the ibuprofen/liquor thing has something to do with the liver. With anti-depressants it has something to do with the two antagonizing each other. With stimulants you don't realize how inebriated you are, and I don't think I need to explain why this is dangerous. I know you didn't ask about these things specifically, but I figured I'd throw them out there.
As for your limits, you can take it slow (i.e. play it safe) until you reach the desired effect. That's not the way I do it, but I don't exactly mind if women take advantage of me.
Jam it back in, in the dark.