Suz, the zip line heights varied, but all of them were up over 80 feet high. The rope bridges were about 30-50 feet up. You are hooked up to a line at all times - there is virtually no risk the entire time. You have 2 safety lines that are hooked up so at no time are you ever not hooked up with at least one line, even going over the bridges. I was scared out of my wits the first couple of lines we went on, but then all was forgotten once I was zipping along over and through the trees! Absolutely stunning. You forget everything else. You could do it!
And the rafting? Well, the guides are so well trained that they aren't even allowed to become a guide unless they can man a raft down the river ALONE. IOW, they wouldn't be 'guides' if they couldn't steer and get a boatload of people down the rivers and rapids with or without the people's help, Know what I mean?? Out of the 8 guests in our boat, only H, my sister and me had ever been and those other five people were so clueless and excited that every time we went through a major rapid, they were in awe. The guide later told my sister that when he needed us the most, we were the only ones actually helping! Hahaha. So that too is fairly safe.