Hello ian. Counterparty uses Bitcoin addresses for everything so you can send BTC or any other Counterparty token or asset to any Bitcoin address except multisig or p2sh addresses. AFAIK, Counterparty doesn't support those more advanced Bitcoin addresses.
Now to view the Counterparty balances, the holder of a address would need to use a Counterparty-aware wallet like Counterwallet or counterpartyd. If you sent tokens or assets to a Bitcoin address that was created in Bitcoin-qt for example, you could sweep that address into Counterwallet. Since Counterparty transactions require fees to be paid to the Bitcoin miners, the address that is being swept also needs to have some Bitcoin in it. I think 0.0001 is enough currently. Hope that helps.