I want to generate a vanity address with BIP-38 encryption for a cold storage paper wallet, how would I go about securely making one? From what I've found, generating a vanity address with Vanitygen does not allow me to encrypt the key. Or is a vanity address advisable at all for long-term cold storage?
Take a look at http://bippy.org.
The main potential issue I see with using a vanity address for cold storage is in spending from the address multiple times. If the wallet software you use isn't properly crafted (i.e., by using RFC 6979) there's a possibility that it will use the same
k value during ECDSA on the transaction, which will make it possible to recover your private key (see this). Note that this potential issue applies to any address for which there is more than one spend, not just vanity addresses. But I bring it up in particular here since the nature of a vanity address implies a reasonable likelihood of multiple spends from the address.