IronPython: How many script engines should I have?
I would definitely try to limit the number of script engines you instantiate. It is a slow process (from my experience), so the fewer times you have to wait for it, the better.
On that note, I would be careful with only 1. I think that scripts might (just might) have the potential to interfere with eachother if you have 1. I'm not sure, but just be careful.
Generally speaking, should I keep one ScriptEngine for the life of the application or should I create and destroy them as needed?