Hi Porizj,
Thank you for your detailed post. Unfortunately, I didn't find any suspicious part in your configuration. Configuration seems to be pretty same as in our dev environment but still we cannot reproduce this issue. I've looked where I could but didn't find anything what could help you. I'm afraid that only way to use Toad for Apache Hadoop in your environment is to choose one HiveServer2 from your configuration and connect directly to it (without zookeeper discovery mode).
BR,
Jiri