Help please with several codes.

1) I have the following code in the custom key stroke section: 

"if (event.change) event.rc = /^[a-z]+$/i.test(event.change);"

try the following code for a popup (the numeral is for the icon on the side ranging from 0 to 3)

app.alert("your text here",1);

2) I have a section with 5 checkbox choices. I need them to start all as required, but once, one of any of the 5 choices is selected, the required and red outline goes away for the other 4 remaining choices please. 

As long as they're named equally the .value of all the checkboxes will change (thus satisfying the required criteria), otherwise you can change the required status through "fieldobject" .required = 0 / 1  (depending on if its required or not)

nb. this.getField("fieldname").required = 1  will set the field to required (although you'll probably want to use the event.target variable in the confirmation tab)

3) Not sure if this part can be done. If they select specific options in a dropdown, it adds new pages/forms to the bottom of the PDF that have to be completed.

I havent been able to add pages myself, from what I understand the adding pages requires javascript with special permissions on the computer itself (perhaps someone else has an answer for this)