I would like to manage my iPhones photos while viewing them through my iMac.

It is hard to see the pictures on the iPhone, so I'd like to view them on my iMac screen and decide from there whether or not to keep, download, or delete them. How do I do that?

There are some photos that I like to keep on my iPhone, and I've already saved them on my computer. How do I keep downloading them as duplicates without individually selecting them?

And finally, most of the time I want to delete all the photos except for a few favorites, after I've downloaded to my iMac. How do I do that?