What is a study nurse? Is it a nurse educator or research nurse?
The nurses I have known who moved into case management from bedside were surprised with the demands of that job but that is in the US. From my experience, it seems like case management turnover rates are high.
What is your area of expertise? I am assuming that you are a bit computer savvy by being on a fediverse platform and if so, what about looking into clinical informatics?
I would be hesitant about moving into a position with lower pay. I've done both bedside and desk jobs as a nurse and personally, looking at all the info you have shared, I would stick to bedside if you aren't burnt out yet until a better paying/hours/benefits administrative job opportunity comes around. But if you are already burned out, definitely do something else or you will be miserable. You can always return to bedside if things don't work out.
Feel free to DM me if you want someone to bounce ideas off of.
Best of luck.