Do miners verify address checksums?
No. The address in the format you're used to seeing it isn't encoded like that in the transaction.
When you send a Bitcoin transaction to someone, your wallet will verify that their address is formatted correctly by validating its checksum, then it decodes the public key hash or script hash that is encoded in the address, and this hash is what is included in the transaction output. The purpose of the address checksum is just to prevent typos; it is not included in the transaction itself.