If you don't want to trust anyone, trust someone with an empty trust list (satoshi, for example).
How is the first score calculated? Some users (eg John) has very high + scores, but the overall trust rating is still 0.
Does it weigh the feedback age very heavily?
Yes. Consistency is very important for determining whether someone is trustworthy. Currently, your trust score will go from 0 to 1 when your oldest rating is one month old and you have 10 positive rating points. I might change the algorithm, though.
In general, what type of people would you add to your trust list? Should it basically be people who you would say that you trust for their opinions, or people you've traded/interacted with?
Anyone who will give useful ratings and will themselves have a good trust list. My most important consideration for my list will be choosing a trust network that doesn't have any incorrect negative scores. This will be especially important for the next few months while everyone has low trust scores. Currently, only one negative rating will result in a warning on the person's posts (each negative rating reduces the trust score by 0.5-4 points). This won't be the case after 2-3 months.
