Could you clarify what you mean? Our multi currency modules allow using multiple currencies on products, either different ones at the same time or changing all to another currency (depending on the module you opt to use) therefore prices in product catalog pages will reflect a new currency.
2. It would depend on lots of factors. We haven’t tested compatibility with the plugin you have mentioned however if it is programmed to support multiple currencies regardless of the plugin that allows using them it should work.
3. Yes, you can create custom currencies with the “Currencies” module.