To be honest, there is nothing different that will happen when you place this script in the working environment. If you have tested this in a lab environment or with a test trigger and it is working fine, then be assured it will work fine in the production environment as well. Looking at your script, there are lot of different functions you are doing within it such as sending email, asking for a callback number, sending call to recording subflow script etc. and if you have tested all these and they are working fine then you are good to go ahead. As a precautionary measure you can still keep the old script in system so that at any point if you encounter any unexpected thing with this script you can always revert to the old one.
If you still think that there might be few scenarios you have not tested then the best thing is to test them and verify. There is nothing better than doing a self assessment when it comes to scripting since you are the one who knows first hand what the end customer wants and what is your script actually giving during testing.
Regards
Deepak
