When releasing the coach, do I still have to pay him his weekly salary?
when you hire a new coach, you will have to pay the one you had his salary for that week imediatly. So in short: yes.
as to the randomness, I indeed also read it, now that you mention it I recall that. If it was a BB, it is true, if it was a GM, it is probably true, but not for sure. BB know all, GM know a lot, but not everything, and some things are not given away by the BBs and for those things the GMs might be confident, but they will never know for sure...
As I said I only based on 2 trainers, so the chance it is a coincidense is prety high, and chances it IS random are big. ;)
I didn't realy keep track, too bad, maybe I should do that and that in about ten seasons we might have some info to draw lessons from. There is a lot to keep track of, and time is limited ofcourse. ;)
They are not your friends; they dispise you. I am the only one you can count on. Trust me.