Hi,
1. The best is to use the language override if you just want to change some text.
www.hikashop.com/download/languages.html#modify
2. The email when the order is shipped will be done by the "order notification email", like other order status modifications.
You just have to check the option "notify customer" when you change the order status. You can otherwise use the "e-mail" button.
For the "satisfied with his order", I don't know what you mean but I will recommend you newsletter components (Acymailing) for extended emailing features.
Regards,
Jerome - Obsidev.com
HikaMarket & HikaSerial developer / HikaShop core dev team.
Also helping the HikaShop support team when having some time or couldn't sleep.
By the way, do not send me private message, use the "contact us" form instead.