Dolphin sometimes takes 2-5 seconds to open on my gaming PC, whereas Nautilus (Gnome Files) is usually done before I’ve even let go of the click.

You might need to look into this more.

It opens instantly on my gaming desktop, Microsoft Surface 7 Pro, and ASUS ROG Strix

I personally like both Posteo and mailbox.org, but they are paid email services.

You can use them for your email, contacts, calendars, and tasks. On Android, you can use Davx5 to sync them.

Are you looking at system apps? It’s installed as a system app on my phone using GrapheneOS

com.android.devicelockcontroller

Looks like it’s an AOSP app

I really don’t understand why schools have this rule (at least in many places in the US). Are they trying to teach you to not practice self defense and just let it happen? Doesn’t sound like a great thing to teach.