One way to think of the portfolio management is to lend your bitcoins at interest. Though that puts a lot of risk on the day trader. He may expect a fee and take a cut on profits. The lender should have some loss protection.
As for the club, I'm not worried about someone encouraging other's to sell so that he can buy, simply because I wouldn't join a large club in the first place. I've been a part of stock clubs in which we buy into the pool, discuss trades, and share all profit and loss weighted upon our buy in percentage. However, the bitcoin market is on accelerated time (or just high volatility). One week in bitcoin is like one year on NASDAQ. The club could also just be a way for people to record their performance, discuss their thinking (both before or after taking positions), perhaps also in real time (irc?). There are already a number of analysis threads in this forum, but we're not really sharing our own wins and losses and learning from each other.
On a similar note. I live far far away from what most of you would call civilization. It's a great place to stash pm but a terrible place to receive metal. I was thinking about a network of trusted holders the world over.