Depends on your needs. Outlook doesn’t offer the Gmail web interface, doesn’t sync with Google Calendar, and doesn’t integrate with Drive or the Google Apps suite. As I mentioned in an earlier reply though, I’ve been using a different app for this that doesn’t require a subscription.

For the Mac users, Kiwi for Gmail has been doing this since June 2015. It’s free for a single account or a one time $8 purchase for multiple accounts instead of $20/year. Windows version is reportedly coming soon. http://kiwiforgmail.com/

Oldest message on top is the correct way to have it. I don’t use Apple’s mail app, but I think the part it gets wrong is not collapsing the thread before the most recent message.

I agree that a phone with the Google Authenticator app would fall into the category of “something you have”, but Google allows you to bypass the physical device by having a set of backup codes which could be “something you know”.

You can use the Lightroom app without a Creative Cloud account. You can save pictures to your camera roll by using the share icon at the top right of the app. The Lightroom app has white balance and exposure compensation, but not full manual control.