Coasting is never a good idea, keep it in gear and either change down as the speed decreases or change down several as you are about to stop. If your back brake is in an uncomfortable position get it adjusted so it works for you, could be it suffered some damage with a previous owner and is bent. Down hill brake before the bend and apply a little gentle power as you take the bend, to keep the bike balanced and in control, Still braking pushes the weight onto the front wheel and is more likely to wipe out. At this time of year smooth and controlled is the way to go. Don't tense up as it makes things worse ( I know to begin with easier to say than do) but if you find yourself tensing then, you need to relax flap you elbows a little so you get movement available in your arms relax your hands don't have a death grip on the bars and try not to take any weight through your wrists. Look where you want to go and don't ride any surface you haven't seen first. If you can't see the tarmac drop back and give your self room.