Is it recommended to also do querying via a Service Bus? As I see it, you should only send fire and forget commands/events.
What is your opinion and/or experience?
Service bus is not only suited to "fire and forget" scenarios. In fact it can be used in many others like "request response". But in contrast to classic remote procedure calls or invocations, service bus provides means to decouple actual requester from actual responder. And that opens the door for easier scalability and/or improved resilience.
There are plenty of posts, articles and books written on the subject of messaging and service bus patterns, and will provide valuable insights and ideas. Just look for service bus or message queue integration, patterns.