For anyone interested, someone kindly suggested me this: https://store.kde.org/p/1160672/
This is so far the best solution I have but it comes at the cost of installing another desktop environment beside Budgie. I would be interested to get a similar result with Budgie.
Powerful workflow / config pattern in Solus?
You can make your own Budgie applet. IMO, that is what I do when I want to have a caffeine mode in Budgie
It can be a widget in Raven
yursan9 Care to explain how? It is about programming a widget or setting one up using built-in UI tools?
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Well, Budgie has gnome-calendar, which you can sync with google-calendar and whatsoever (look at gnome online accounts).
If you pin gnome-calendar to the taskbar, then it needs one user action (i.e. click on gnome-calendar in the taskbar) to show your calendar events.
On Gnome Desktop (and KDE Plasma as well) calendar events can also be displayed in the calendar widget (accessable via click on the clock widget - like on windows). So that results in exactly one user action again to show your events: click the clock 
Here is a scrreenshot of how the gnome clock/calendar widget looks like
Here even another clock widget for KDE Plasma with google-calendar support:
https://store.kde.org/p/998901/
but all the same: there is always just one click needed....
- Edited
[deleted] My question was: It it possible to satisfy the constraint on Budgie? Your reply suggests that a similar, but different constraint can be satisfied: It is possible to display calendar along with events, without scheduled alarms, on a different desktop environment. So neither the desktop environment, nor the conjunction of both calendar events + scheduled alarms components of the constaint are shown to be satisfiable in your reply.
Still, thanks! I am now wondering whether I should ditch Budgie for either KDE Plasma or Gnome.
Nycticorax You need to program it. I know my solution is not really practical for some people.
yursan9 Python, Vala or C? Are these all the languages supported by Budgie widgets?
I think I know enough Python to do that. I think I will have to head to https://dev.getsol.us/ then.
- Edited
Nycticorax You can use Python. If you already familiar with GTk, you only need to inherit Budgie.Applet and Budgie.Plugin. Here a link for you to get started: https://github.com/yursan9/budgie-caffeine-applet
yursan9 just know that python is a legacy and if you intend to share your wor
Nycticorax python support is legacy. You can start with it if you are familiar with this programming language but Vala or C are best options on the long run.
yursan9 very much on point, thank you, will save me a lot of time!