I agree that there are problems to grouping. However if it is dynamic, based both on what you are sharing and what you are searching for, and you are able to belong to multiple groups it should offer benifits.

As for packets containling multiple queries. Is bandwith more an issue of packet size or number?

Is there data on how much of the query bandwith is taken up by the top 10 or 20 searches? I imagine it is quite large. If ultrapeers could cache the results and give extra ttl to others results might be better.

BTW, when will we see a release of cultiv8r? I would love to try your client out. Email me at gnutellafan@hotmail.com