To enjoy full privacy it’s always best to run your own node both for Bitcoin and Monero.
Supply CAN be audited, just need the person to learn a little bit technical skills iirc 🙃
You can use a remote node without problems. Feather Wallet is a good wallet that includes a list of trusted remote nodes (including onion nodes over Tor). AFAIK Cake Wallet and Monerujo (mobile wallets) also include lists of trusted remote nodes. Otherwise you can host your own node and connect your wallet to it.
Except we can't verify supply, it appears that to enjoy the privacy features u have to run your own monero full node. If you don't, privacy and anonimity set are bad. This is what I've heard from someone more technical than me, could you confirm ? @allark