iCloud photo storage on mac and iPhone

I would like to keep all of my original photos to my Mac and back them up in iCloud ( i currently have about 2 TB of photos) I would like to be able to download pictures from my phone onto my mac as well to store the originals there (just got a new phone and started completely fresh with pictures). I set my mac to download and keep originals. My question is what do I set my phone to on iCloud? I'd like to see my iCloud photos but I don't want 2 tb stored on my phone since it only holds 1 TB anyways. If I set download and keep originals will all of the iCloud photos from my mac be downloaded onto my phone? But if I choose optimize phone storage, how do I get new original size photos saved to my mac after I take them? I think you can download the originals from I cloud but will I be able to tell which ones need to be downloaded to my computer or does it happen automatically with the setting I selected. Please help it's a little confusing!