1) Can your environment trigger an episode of depression? (I have read that it doesn't).
Yea absolutely, very often there's a trigger. Because bipolar is so unpredictable and neurologically ingrained sometimes it "just happens." Things like break ups, deaths, alcohol use (it is a depressant), etc can trigger depression. The tricky thing is people very often think they are depressed when they are grieving, and they are not the same thing. But people pre-disposed to depression, like people with bipolar, can get plummeted into a depressive episode. If you meant your literal environment, if you were somewhere or with specific people that bring back bad memories or you associate with a depressive period of your life that could totally bring it back.
2) Can your environment make your depressive phrase worse? (I have read that it doesn't).
Pretty much what I said above. Also keep in mind that bipolar is wildly different between people and everyone experiences different triggers and severity and such. I get funeral mania, which is where I sometimes launch into a manic episode after attending a funeral of someone close. It's not very common but it does happen.
3) Are you much worse around some people than you are around others during the same depressive phrase?
Oh absolutely. There are some people I feel very comfortable around. Friends that come over to just spend time with me when I'm in such a down phase. I'm absolutely awful to be around, I've had a friend come over to study for an exam while I sat at my desk crying and studying for my own exam, but she did it because she cares about me. When I get really depressed it gets so difficult to be around people. Like I forget what it's like to be a functioning human being and I have no idea how to act around others. Just feeling severed from people and alone in a crowded room, so to say.
4) At what age did your symptoms start?
In hindsight, they started in middle school, probably around 12. A lot of times people can notice symptoms in childhood and there are unfortunate cases of childhood bipolar. I also know people who didn't show symptoms until after 50, due to traumatic events like death of a spouse and such. Again it's very unpredictable and people predisposed can show symptoms and different ages depending on a number of things, like events. Unfortunately we don't actually know what or why bipolar starts up.
5) What do you do when your bipolar episode affects others who care about you? How do you handle it? Do you separate yourself from others, do you apologize, do you expect others to tolerate it no matter what, because bipolar ism should be treated like a physical disease?
It's a tough thing really. When I'm depressed I seclude myself because I don't know how to function among people and I know I'm miserable to be around and drag people down. Depression also makes me feel awful about myself, which is true for just about everyone, and I feel like I have to apologize for everything. When I'm manic I don't realize it really and don't understand why people wouldn't want to deal with me or be around me constantly because I am the most hilarious and beautiful guy in the world (I'm also usually psychotic with crazy delusions like this haha). There will always be the debate about how people view mental disorders, especially those that affect decision making. Bipolar affects everyone. Most people don't experience periods like that and can't imagine what it would be like. It's impossible to imagine having occipital lobe damage and being unable to recognizes the faces of people you love. Similarly, bipolar affects the prefrontal cortex which is the primary component in decision making. People have done awful awful things after damage to that part of the brain. Anyway, enough anatomy talk

but it's a very good demonstration of why it's not something you can just "get over."