Hi man, I think that maybe you can use task in other way, I think is too complicated to try to do what you want.
If you wanna see a task, use a workspace for the project of that task, this way you are going to see it all the time. You don't need to have a task asigned to you to see it.
If you wanna know what happend with a task, then suscribe yourself to that task.
If your partner needs your help is better if he ask you for the help with a new task, a sub-task or asingning you that task by editing it and telling you what does he need in the description.
A better use for a task asigned to several users is, for example, if you need that 5 persons read an inform. You asign the task to all of tham and you can see who has read it by seen who has complited the task.
I hope it helps you.
Good look.