Depending on how you look at it and don't have enough information you might say that this information is not true. But this is not the case.
It's definitely not true. The transactions are fake. You want users to believe they are real.
Agreed. This is misleading, while they're in the business of absolute trust.
we want to give the clients an insight into the transaction situation without publishing specific client data.
Just put a banner that says something like "We average X transactions per hour".
Or a popup saying for instance: "On average, someone creates a Bitcoin Mixing Order using the Stealth Pool every 4 minutes" (or whatever number of minutes is true).
Popups are annoying as hell, so now it's misleading and annoying. I'd say get rid of them entirely.