Hi,
You should have a look at John Brinkman's blog: http://blogs.adobe.com/formfeed/2010/02/big_and_complex_forms.html on this topic.
The number of scripts is one aspect, the main concern is what events are the scripts in. For example, layout:ready fire very often, so if you have a lot of objects with script in this event, performance is going to take a hammering. This is especially true when the form is dynamic, in that you are repeating instances of an object - as this fires the layout:ready event across all objects that have script in this event. Similarly calculate event will fire when objects referred to in the script change, therefore if a lot of objects are interlinked, it can have a cascading effect.
You may want to consider limiting the max number of times an object can be repeated.
I have an exercise in script events here: http://assurehsc.ie/blog/index.php/2010/05/how-often-events-fire-and-their-sequence/
Possibly consider using script objects and functions to make it easier to develop and maintain your script. EG one script accessed by different objects.
Niall