You had to have disrupted something else while you were changing the serpentine belt. I've driven a short distance without the belt at all so just changing it shouldn't have any side effect like not starting. Check all your electrical connections and be certain you didn't dissconnect anything while you changed the belt. It's possible that your battery is dead if you drove a distance without the belt in place. The belt is needed for the alternator to charge the battery but this would be the only way I can think of that changing the belt would cause your car not to start.
No, there is no connection.
Check the fuses.
That would be a judgment call on what the old belt looked like.
No
Many things can cause a serpentine belt to come off. Most likely, it slipped off, or the tensonier that holds it in place was not tight enough.
frozen pulley
Start with serpentine belt, then belt tensioner or pulleys, maybe water pump or cam shaft distributor
have you changed any pulleys alt. etc.make sure they all have same amount of groves for the belt to seat into!some have6 some 7 check it out
the most likely cause would be an improperly tensioned serpentine belt
If the belt is too loose or not there then yes - the water pump runs off the serpentine belt. If the belt is too loose or not there then yes - the water pump runs off the serpentine belt.
serpentine belt has nothing what so ever to do with break fluid.only reason it would leak thru serpentine belt replacement is if a brake line or part was broken by accident while installing belt
Loose or worn out serpentine belt.