high ram usage, pathetic connection handling and paranoid block lists are just part of it, but the way internet protocol and the emule works is the ultimate reason why it doesn't work. It's not about trusting, its about it being pretty useless

You need to understand how mpaa gather ips to understand how useless it is. I always end up repeating myself, and I've written about this numerous times over at fileheaven.org, but there search is down. I'm not sure if i ever had to post it here, but feel free to post this in the topic if you wish

To get your ip, the scanner ip address merely queries the network for sources (via the server which has your ip logged, and the files you are sharing), this is then sent to the scanner and they have you already, with zero communication between your two clients. Any firewall or peerguardian is pretty useless because of this. Add on top of this the source exchange technology in emule and you have yourself other clients sending your ip as a valid source for the file. So to answer the three points.

1. pretty irrelevant, they get your pc through both direct and indirect communication. Block lists are pretty limited too, and i've noticed that lots of the ips aren't mpaa/riaa/nazis/aliens at all, they are home users. The only issue is whether a pc actually exists at the ip address if they get it indirectly, but assumption allows letters to be sent out anyway. There's a lot of paranoia surrounding what these organisations actually do, most just send out letters, and take no further action. There are of course show trials you've read about, but from what i've seen most people get a letter then carry on.
2. true, but regardless, if you have blocked them, they still have your ip from searching and source exchange
3. it is poorly programmed, reminds me a lot like zonealarm in this respect. but the reason is that you still appear as a source regardless of whether you block or not. They can not get any of the file from you, but they don't care, and as illegal as it sounds, this is irrelevant for them. You are still sharing the file and they have 'evidence' of you doing so.

It is pointless in its current form, only by blocking them from connecting to the network is it possible to block them regardless.

It's a shame fileheaven.org search is down, I've gone over this a few times for people who have posted things like "I'm using peerguardian and got busted" or posting they are 'safe' because they use it.

Don't get me wrong, I'm not discouraging use of blocking, I'm just saying it's not much good. If you have the same blocklist on a firewall and on peerguardian, ditch peer as its just pretty inferior. It's a hobby programmer making a tool to peddle to people who think its some kind of cure all solution, the firewall is design for security purposes and is more suitable for blocking connections.

Also uses a damn sight less sys. resources. I have a hardware firewall and use an emule ipfilter if you are interested in what form of 'protection' i have.

Hope that answered the question.