Yes, that's correct. You would have to use 'ice.ace.jq' instead of '$' if you want to use our version of jQuery. You could also add your own version of jQuery to work alongside the icefaces' version. That's why we rename ours to 'ice.ace.jq', but I would recommend just using our version of jQuery.
You don't necessarily have to change every occurrence of '$' for 'ice.ace.jq' in your code. You could simply put your code inside an anonymous function that automatically gets executed, which takes an argument that you name '$', then you simply pass 'ice.ace.jq' as the argument. It would look something like this...
// your code using $