How to use the following functions in MAC OS?

Question

Apple Photos

Friends, hello!
Have successfully used iPhone\iPad for many years. Recently I bought a MacBook Air and had a few questions. Googling didn't come up with an immediate answer.
1. When you try to set up notes synchronization through your gmail account, nothing happens. I put a tick on the notes in the accounts and it disappears in a couple of seconds without errors or notifications. iPad - iPhone sync is working. What to do? Gmail corporate on your domain!
2. Turned on iMessage. It works, but how do I download old messages to my Mac?
3. Mail downloaded all the mail from my gmail account. This is about 16Gb. How to teach him not to do this, but at the same time retain the ability to search in the mailbox? 16Gb is a pity to me.
4. Is uploading from iPhoto to iCloud media library implemented at the moment? So far I see that 999 photos have gone to the photo stream, but they are not visible on other devices. Somehow crooked. Wait for the release of the promised application in 2015, and now do not waste time organizing photos?
5. Is content downloaded from iCloud Drive or are only "shortcuts" visible, or is some compromise being used? The drive contains 45Gb of various content, and on a Mac, the folder occupies 15Gb. What did I miss?
6. Question with * :) Are there ways to synchronize HISTORY between Chrome and Safari?
I will be very grateful for the answers. It seems that I don’t want anything space from Mac.