If you are going to create something View right is definitely not going to be adequate.
If the PM is not PM of both projects then he or she would need Project edit rights to the one where he or she is not.
Further I think Edit Project plan is required.
I tend to disagree with the statement in 2. IF that were literally true you would not see the Dependency tab unless there were a dependency which meets the criteria.
How would you then create dependencies?
Just created these
and have no problem seeing this
while in the other project looks like this
Is that statement restricting you from doing what you want to do?