Too many questions in few sentences. I will split it up like this.
Q) How can I protect the script
A) Open you qlikview document, go to script editor , File menu --> Crate Hidden Script --> It will prompt you to enter password. Copy all your script here. By this your script is secure.
Q) allowto only viewing the report in ?
Yo can play with os user function
Look at the below post.
Q) As can also block the export toamong other means of ?
Yes, you can block Excel export from users, I can think of two ways
1) You can disable exports in the document properties, security tab.
2)Another way would be disabling all exports in the server configurations. QEMC--> Documents --> User Documents --> Server --> Availibility --> Print and export to excel option --> Specify the users you want to allow this features.