To change the cambelt on the 1.6 you do need to remove the belts for the waterpump and power-steering pump afaik. (but this should be relatively straight forward job)
When it comes to cam-belts, better safe then sorry. When in doubt, replace.
I've had mine done recently as I had no idea when it was last changed. But due to all the markings around the engine bay I suspect it was about 7 years ago, so I had the belt changed just to be sure. The belt itself looked almost new, but the tensioner had a noticable tick when rotating it, meaning the bearings were on the way out) If you are going to change the belt, I recommend also changing the waterpump and auxiliary belts while you've got everything off. It's not that expensive but it means you don't have to take everything back off when the pump goes.