We basically attempted to get the bots to match each metric that we were measuring server side from a smaller sample of players during closed beta. The peak concurrency during closed beta was something like 2000 players, so we multiplied each metric out to get a target. Here are a few examples of metrics:

Chat messages per second

Party creations per second

Average party size

Number of zone transitions per second

Average number of open zones per player

Character saves per second

PVP Match list requests per second

And so on, and so on.

Certainly bots are not going to be the same due to the issues you mentioned, but we do the best we can! We didn't simulate all kinds of connection issues a real player might have, but we did match the non-graceful connection termination metric.