1) Is it possible to have more than one sender for the same queue. My opinion Yes it should be possible. The messages will be stored inside the buffer.
2) Is it possible to have more than one reciever for the same queue? My opinion NO, because = who shoul take the message is more than one task are able to receive the message.
The reason the answer to question 2 is yes is because tasks are blocked in priority order. If more than one task is blocked on the same queue then the higher priority task will be the task that receives the next data. If both (or more) tasks have the same priority then the first task to block will be the first task to receive the data.
I’m a fare way down the route of writing some more comprehensive and printable documentation, but unfortunately time constraints mean it will be a little while before this is published.