Do all transactions have at least one output that contains at least one bitcoin address Do all transactions that are included in a valid block have to have at least one bitcoin address as part of their outputs (vout)?

I found this to be similar: Are Bitcoin transactions permitted to have no outputs (i.e. all inputs become transaction fee)? although not quite the same.
No.  A notable example of a pubkey script that doesn't typically include addresses or keys is the nulldata standard transaction type.  Examples of pubkey scripts that include public keys but not addresses are pay-to-pubkey (P2PK)[1] and "bare" multisig.

Although I'm not absolutely sure, I believe its allowed to have an empty pubkey script.  (That is, the compactSize uint that describes the size of the pubKey script is 0x00.)

Note: Bitcoin Core's getrawtransaction RPC, decodetransaction RPC, and other RPCs will display the public keys in P2PK, bare multisig, and redeem scripts as addresses---which can be a bit confusing.

[1] P2PK was formerly used for most coinbase transactions, but that usage has mostly disappeared on mainnet with pooled mining.  It's still a standard transaction type and quite common for coinbase transactions on testnet.