About the people assuming you're straight and looking for relationships as a source of small talk, I got asked about that on my second day of work, the day I got into a car crash on my way to work. Apparently I need to get out more and go clubbing or something since I never been on a date before, because that's what I should be worrying about after a wreck and trying to not call of work due to the pain. Actually my aunt was pretty bad about it too before I got hired asking me what kind of men I like, do I prefer white guys or black guys, etc. Maybe it's just the kind of person I am but I always found those questions to be odd, even more so in those kind of conditions. I was applying for work not a dating site.
<honorary sympathy like>
When I was in my 20s, I used to get this question all the time from strangers and my husband's family: When are you going to have kids? I would calmly explain that I was indeed in a happy marriage, but kids were off the table due to genetic reasons. The answers varied. A few suggested adoption, which is very expensive. We looked into it and it was $20,000 just to get started.
Then it was, "Oh well, you could get pregnant if you want to, right? What do you mean you have no interest?" The very idea that kids weren't apart of our long term plans in anyway blew their mind.
The worst was being told by someone that was pregnant, "You're just selfish and that's why you don't want kids." Um, no. I actually really like kids and love spending time with them. However, my husband and I knew that we wouldn't make good parents. Plus, fun stuff like Celiac's and PKU runs in Sasquatch's family among other things and we weren't going to risk that happening to our kid.
Still catching up on the thread. The "gay lifestyle" question is one that I hate as well. I'll post about that one later.