Hi,
1) In the backend, go in the System => Currencies.
You can configure and currency and change his display.
2) There is several solutions.
If you don't have free products, I could propose you:
* Set the stock to 0: so it would be not possible to put the article in the cart
* Set the price to 0 and change the translation "FREE_PRICE" from "free" to "ask for a price".
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.