Can I prevent "Photos" app from loading? I really dislike using "photos" app it is simply an un needed app for me because I have minimal HD space and do not need a back-up and do not want a cloud back-up either. I would love it if I could prevent the app from loading altogether.
When you say loading you mean Photos will open once you connect a device to your mac?

Use the Image Capture app to configure what app is loaded for that device. You can turn off loading of Photos, too. This setting is on the bottom left, you might hat to click the arrow-up sign to see the app selection box.