Irme,
There
are various maintained/Buff Effects window mods that already have the timer you are looking for (
example). Just because something is not offered within the ThorUI updater, doesn't necessarily mean it cannot be used (that's the biggest thing I like about ThorUI....Faetyl tries to keep it non-inclusive, meaning other author's work can be used along with it without breaking the entire UI).
In regards to the hotbar timer thing, I believe I have seen past discussions about this not being able to be done.
Here's one thread I found on it.