Photos

No, Apple aren't listening here. They don't promise to read anything on these forums, which are for users talking to other users. However, they do promise to read feedback and feature requests offered here:

https://www.apple.com/feedback/photos.html

It used to be different in the early versions of Photos. Initially, hiding a photo would only hide it from the Moments and Collections and Years, but it remained visible in the albums. Apple changed this behaviour in the recent versions of Photos. Many users complained, that hiding a photo would not keep it secret.

Now the only way to keep hidden photos in some album while hiding it from the Imports and other library views is to use a smart album. If a smart album includes a rule "Photo is hidden", the hidden photos will be visible in this album.

But do want to hide your photos, or just to weed out the All Photos and Imports album?

If you want to use the "Hiding" to remove photos from the "Imports" album after you added them to an album, you could create your own "My Imports" album, where you suppress the photos, that are already in albums. For example, this smart album is showing all photos, that I imported during the last 30 days and that have not yet been added to any album:

Match all:

• Date Added > is in the last ... days
• Album > is not > Any

Control (right) - click on the photo and select "Hide 1 Photo" from the contextual menu.

Warning: If you use your library as a screensaver or rotating desktop pictures or create slideshows hidden photos will be displayed in them. Hiding only removes them from the general All Photo view, albums, smart albums and slideshows (Photos V 5.0 in Catalina). If you make a slideshow from an album with hidden photos they will be in the slideshow.

No. Hiding a photo hides it everywhere (in Photos V 50). You can test it by selecting a photo in an album, hide it and watch it disappear from the album.