I agree with all your comments. However, I am still of the opinion that you should always request politely of the 'original owner' of the information and, not only that, acknowledge their contribution when posting the same information in your tree. Of course we should share, but someone who downloads information by the shedload, including the most private thoughts on recently deceased relatives (in my case, a personal bio about my beloved mum) just so that they can add numbers to their tree is wrong.
There, had my rant. Have a great day!