There’s a section with FAQs and how-to videos where these questions are answered.
- When you login to CW by default BTC and XCP are displayed for each address. There are thousands of Counterparty assets registered so other assets aren’t shown by default. You can send GEMZ to any CW address and you’ll be able to use them.
- How can I export (obtain) private key for my Counterwallet address? - private key
- Why do I need small amounts of Bitcoin to do things? - small amount of BTC required