iPad to replace laptop as only non-phone device: Questions re: my Photos and Music libraries

When my MacBook Pro needs replacing I am considering going to an iPad. My concerns are mainly how to handle my photos and music if the iPad has 64GB or 128GB storage. Presently I have 20GB of photos in Apple's Photos on my laptop (backed up to iCloud and an external hard drive. I also have 175GB of music (combination of my own CDs and iTunes purchases). I have iTunes Match and I recently joined Apple Music and have downloaded music from it to my library.

I would greatly appreciate having the following clarified, confirmed or corrected:

1. MUSIC: As I am prepared to use Apple Music exclusively, I assume I don't need my current iTunes library on the iPad as it will exist in iCloud Music Library in its current form. I will be able to listen to whole CDs or individual songs as I do now. In addition, I can keep it on an external drive in the event I ever leave Apple Music.

2. PHOTOS: I can transfer the 20GB of photos from Photos on the laptop to Photos on the iPad. I can also keep them on an external hard drive as a backup. However, for new photos with my DSLR camera or iPhone taken after I have the iPad, I will be able to store them in Photos on the iPad but not be able to back them up on an external hard drive (unless there is a way to do so I don't know about).

Thank you.