Would the fact that he's got so much going on in his 6th House indicate stress and difficulty in this area of his life?
Yes, broadly speaking. Someone with many planets in the trik houses will have more unpleasant life experiences.
But broadly speaking is not good enough, really.
Focus on house rulers, rather than planets in houses, if that makes sense.
So if the 7th house ruler is in the 6th, it's likely that relationships are troubled, marked with conflict, hard to balance, cause illness etc.
The dignity of the 7th ruler (and general signifier = Venus) will decide how bad/good the experience is. Malefics with or aspecting the planet bugger things up worse, benefics improve things, according to their strength and dignity.
I use the dashas to organize a person's astrology in time, so rather than looking at the whole chart, you focus in on the active planets for any given period. If you can do that, you can also make broad predictions, and then more specific predictions.
Here are some info I can provide about him to help in the interpretation. For starters, he's a virtual friend, I haven't met him in person yet. But we've talked much over the internet through the years. He's gay like me, and pretty open about with family and friends. When I met him he was struggling with some emotional problems and seeing a psychologist. He's very interested in psychology, astrology. His passion is acting and that's his major in college. He told me his parents got divorced when he was either a child or a teenager and that has left a feeling of guilt somehow in him, although he told me he was not the cause of their divorce. From what I talk to him, he seems to go through periods of intense emotional neediness and loneliness to periods of more self-confidence and extroversion. He told me his love relationships haven't quite worked out for him as well.
Well that's something you can hook on. Check out the 7th house/ruler and Venus.
Sidereally, both are in the 6th house, with Mars.
Mum and dad house signifiers are both Mars, also in the 6th
Acting; Jupiter in the 1st ruling the 5th? I would think so.
I'm worried about giving him an answer soon, because I made a promise by telling him that I'd try to interpret his chart (silly me, never do that again!!!) and I've been delaying that.
Ha, I've done that a lot. Biting off more than I chew.
A flattering way to get out of it might be just to come clean and say you're only just beginning to get into astrology, but you wanted to get to know him better.
And then continue to interrogate him about his life and use his chart/life to get to know astrology. Win Win