Thought I'd update this thread with my experiences so far.
Some of you may have seen my winner screenshots in the threads, but to cut a long story short, I now have a total of 5000 euros to withdraw.
Positive notes:
Within a few hours of me requesting the first withdrawal, the standard documents request email was sent to me.
I replied instantly, and 10 minutes later, they replied asking for a different bill, I resent immideately, and 2 hours later, they had approved the documents (they state it can take 2-3 days to approve documents, so I was pleased at this point).
Negative notes:
Payout times state 2-5 days to process, and I sure as hell hope this isn't 2-5 business days (see next point). Unsure as to whether this is a normal Rival Casino thing though.
Max withdrawal per day is 1000 (again, is this a normal Rival thing?).
Will update once I receive some money.