There are MQ-Client and MQ-Server protocols, contained within the SOA bundle which also includes Web Services. You can buy this bundle standalone, or with the Web 2.0 bundle (also includes Web and Multimedia, Rich Internet Applications, and Mobile protocols).
For scripting, I suggest checking out Service Test 11.2. It is far simpler than scripting MQ in Vugen and the scripts can be used in LoadRunner tests (assuming you are licensed as mentioned above).
No, but the same concept should apply. You could create a C-Template user and create custom messages to go into queue's while you monitor input and output.