The Librem 5 already has GNOME Clock, so it has a working alarm clock, stop watch and timer.
It has a Gedit, so you can make lists, but maybe you are thinking about a specific list app.
It has the GNOME Calculator, so you can do math.
Yes, you can “add web stuff to home screen”. You can take any web page and add it as an app to your desktop, so you can go to a web site that reports the weather and add it as a weather app to your desktop.
Yes, GNOME Web (epiphany) can run JavaScript.
Bluetooth is now working.
You can use GNOME Sound Recorder to record voice.
The cameras aren’t working right now, but it is planned to use Cheese for video recording.
Lollypop is working in the Librem 5 for playing music. I have no idea if it can be played in the background right now.
You can install Slack in Linux, but it probably isn’t designed to handle small screens and I have no idea if an ARM port is available, but I doubt it.
Dropbox works in web browser, so you can use it that way.
I have no idea what most of your specific apps are, since I only use apps found in F-Droid on my phone. If it runs in a web browser, then it will work in the Librem 5, but you might have to change certain security settings in the web browser to get it to work as you want. For example, you need to allow the web browser to allow sharing of the geolocation, and I’m not sure if the Librem 5 will allow GNOME Web to access the GNSS, so you might not get precise location.
I recommend that you install Qemu and download the latest image of the Librem 5 and run it on your PC to see what apps are available, and then try installing the other apps that you want using the apt install command. See: https://developer.puri.sm/Librem5/Development_Environment/Boards/qemu.html
There are a lot of things available in GTK + GNOME, but they aren’t using the libhandy classes and they haven’t adapted the dialog boxes, so they won’t work well on a small screen. For example, you can install Gimp to edit photos, but it will be a very painful process without a mouse and the interface is designed for a large screen.
I expect that a lot more GTK apps will be adapted for the Librem 5 within six months or a year after release, but don’t expect a lot of GTK software to work well in Q2 of 2020 when the Evergreen batch starts shipping.