I'm Russian and I can say that's not our proverbs or smth like that. All I can say, such talks are common in Russia between men. From the first phrase I could say that may be he wanted to point out he understands your will to work hard for whatever reason, but he worries about your health and wants you to relax a bit.
He feels like you are good fellow and thinks you both can talk less officially. Or he tries to look more American type from his point of view. Tries to show you that he cares as he thinks all Americans act like that.
Some people really don't think they ask something inappropriate. May be he is of that type.
But the last mention isn't appropriate even for us. He checks your long-term plans if you are going to spend more time for work or to establish your life.
It's hard to say what he is looking for. It really depends on your boss' mentation. What he does want to hear. In Russia we often say something like "Of course, the work in your company is my top priority, I want achieve a, b and c (and etc.). Family? What is it?" Because most of them expect us to pay more attention to work. In their mind family ruins all that. On the other hand (but it's really really rare) there are people who feel themselves like fathers/mothers and they expect you to be more sincere.
I wouldn't try to guess who is he and would avoid responding such questions. Say something general like you haven't decided yet, some joke, or say what I've written previously and do what you think you should do.
Update:
Wow, wow, wow, @Blam... I would call it "cultural difference". In 2nd case his boss clearly stated: previous person was uncomfortable with his workplace. Some people would leave the company if they get inconvinient desk/laptop and etc. It's widely known psychological fenomenon when southerns can't understand notherns. By the way, my American boss always drops in and asks whatever he has in mind and in our company it is considered as team-building. He just tries to predict whether we satisfied with our role in company.
Either way, give him a hint that you are uncomfortable with such question. I would be shocked if someone would consider me as harassing them.
My experience
I'm working as web-developer for America-based company. So our stuff is half-American, half-Russian. For half a year I was asking my management to relocate me to some place in office (for a reason I would omit). Not so long ago we moved to a big office and I got my desk in separate room with 1 other developer. He works mostly from home so I got the whole cabinet for myself (Bwahaha). So every coworker, manager, boss who passes my door by asks me if I'm feeling lonely. They don't understand that in fact... I like it! But from your point of view the whole company is harassing me D:
In case you won't leave this company
We, Russians, get along with Indians, Italians and Texassians :D We like unofficial way of speach. Even at work. Thank you for your post, though, I will be cautious when asking my foreign coworkers about how they feel about... anything.
And yeah
Never ask Russian "How do you do?" Because we will tell you How, When, Where and For how long we did it. And no sexual background here, just beacuse in our culture we don't ask such questions for politeness. We really ask person about his weekend and really will answer how we spent it.