Are there any other things that are shared in the trust, or just companies that you own?

It's really not about the companies nor is it even legally binding in most cases with these arrangements(there is a lot of argument for/against making it legally binding). This idea dates back generations when joint families were more common.

Also see this if you haven't:
http://news.ycombinator.com/item?id=3071593

Has it pushed you to take more financial risk due to the fact that you have fallbacks?

This plays out every single day in one way or the other.

Example 1: One of the core points which I grew up hearing from my dad is that my money isn't really mine--it's the family's. Where as in American culture we largely teach kids independence from an early age, my dad never made me feel like I have to work as a teenager to have pocketmoney. His money was mine. What if he didn't have money to give me? I'd be expected to be sensitive enough to understand and work - so I can help the family(not so much myself).

Example 2: Last year I was in school and my (normally well to do dad) hit a rough patch. Our entire family finances were fucked. So I picked up a few coding gigs, worked my ass off and made the checks go straight to my dad.

Of course, my school friends thought I should be loaded at the end of the project. When I told them 100% of the money went to my dad, they were shocked. Some even tried to tell me "bro you're stupid!" :) May be. But that's my culture :) And so far I love it!

Example 3: Earlier this year, I just packed my bags one day and moved to NYC to live with my brother indefinitely. As I understand, this is not common in American culture. And even when a really close friend lets you do it, it is seen as "owing" a favor. But in our case, I did not owe my brother a favor or explanation on why I was going to live with him in his one bedroom apartment. In fact, I'd have to give an explanation to my family if I decided not to live with him. It's expected that if you live in the same city, you live together if you are family.

Oh btw, I have a full-time job now but my brother pays 100% of the rent. And I'm saving up cash from my job so one of us can potentially quit in a few months and take a shot at the start-up game again. None of this is planned or negotiated well in advance. My Dad could call me tomorrow and ask me for 100% of the money in my account and I'd send it without reservation. He'd do the same for me--though out of respect for being the father, he has more right to question me about why I need money than my right to question him. =)

Few months ago I had a major financial disaster when a client turned out to be fraudulent, putting me over $10,000 in the red. That's a lot of money for a freelancer. This is when I was able to call up my dad and pretty much the problem was immediately taken care of(he's doing a lot better now financially than last yr).

In a few years, my dad will be retired. He won't be getting a social security check from the gov and he barely has savings for retirement because he mostly invested them in his kids--knowing they'd take care of him after retirement. So he'll be getting money transfers from all of his kids every month after retirement.

That's our social security =)