I'm in a similar situation, my 3 year fixed with KBC at 4.49% is up next month. My fixed rate will revert to the same tracker as yours.
I rang KBC a couple of months ago to verify this was still the case, and they confirmed that my loan would still be reverting to a tracker.
There was a discussion on Matt Cooper's programme on Today FM yesterday evening about someone who had only a verbal agreement with their lender to revert to a tracker at the end of the fixed rate term, however when the fixed rate ended they were placed on a Standard Variable Rate, and because of no written agreement their entitlement to a tracker was tenuous at best.
However, as you and I have written contracts with the bank to revert to the tracker, I imagine (I'm no legal expert) that the bank can not revert us to SVRs without our agreement.
I'm really looking forward to having some extra cash every month as you can imagine!
I'm not sure about your other questions but I find KBC's customer service very helpful any time I've been in touch with them.